While desktop computers are firmly established as music-making devices, laptops until recently have largely been relegated to more mundane chores such as word processing, spreadsheets, and e-mail. But that's all changing now, as faster processing speeds and the development of software-based synths and samplers have transformed portable computers into potent musical tools, particularly suited to live performance. How do today's performing musicians use these amazing machines?

I spoke with performers who employ laptops to make music in a wide variety of styles. These musicians use their laptops to replace entire racks of synthesizers, to trigger theatrical sound effects, and even to create entirely new types of instruments. Laptop computers have become a welcome and liberating part of live performance in all kinds of scenarios-performing on the road in national tours with big-name acts, playing original songs in nightclubs, or creating abstract experimental sounds in the halls of academia.

POWERBOOKS ON TOUR Without question, the musicians who have benefited most from the power and portability of laptop computers are the road dogs, those unsung heroes who spend most of their lives lugging gear from one show to the next, night after night. I spoke with four touring musicians who had great things to say about their Apple PowerBooks running the Unity DS-1 digital sampler and the Retro AS-1 analog synth software from BitHeadz.

David Hampton is the keyboard technician for Herbie Hancock and worked with the Maxwell Live '99 tour. For that tour, Hampton designed a PowerBook-based system that provided sequenced horn and background parts to support the live music. "The whole secret is not taxing your system too much," he says. "You take the material right out of the studio, select what you're going to use, mix it in when you're in rehearsal, figure out what the band's going to play that sounds thick and what you're going to play that fills it up, then say, 'Okay, now, let's make this thing portable.' . . . It was a challenge to do it on laptops because of budgetary considerations, but it works like a charm!"

Hampton also described how software synths have replaced Hancock's hardware racks. "We've reduced Herbie's whole rig to BitHeadz, so he no longer carries around a bunch of synthesizers; he carries around a virtual rack on a PowerBook." He recommends Unity not only for its superior audio quality and portability, but also because it's considerably less expensive than transporting a lot of hardware. "I don't think we'll ever need to use racks again," Hampton says. "They just weigh a musician down!"

HAVE LAPTOP, WILL TRAVEL Harry Sharpe, on the road with Wynonna and Naomi Judd, completely agrees with that sentiment. Sharpe used to tour with a large assortment of rack-mounted gear but now relies on a Peavey C8X piano and a G3 PowerBook running Unity DS-1 as his entire keyboard rig (see Fig. 1). "This thing has totally revolutionized everything I do," he says. "I'll probably never have to buy another keyboard again." Not only does the software reproduce a wide range of instruments (including his favorite Wurlitzer organ), it lets him bring a virtual choir on tour for songs like the Judds' "Love Can Build a Bridge." He took choral phrases off the original recordings, loaded them into Unity, and played them along with the live performance. It sounds great, and you don't have to book hotel rooms for 50 people.

In Donna Summer's band, both keyboardists, including musical director Michael Hannah, use PowerBooks as their sound generators. But unlike Sharpe, Hannah relies more on BitHeadz's Retro AS-1 software synth to produce the characteristic sounds of disco. In fact, he likes the modern digital versions even better than their analog ancestors, because they don't have any noise or oscillator shifts and they offer a wider frequency range. And portability came in handy during a recent taping of VH1's "Divas 2000" show, with its numerous set changes. Hannah doesn't even take outboard gear to recording sessions anymore, and he says that he's never received any complaints from engineers, even in an exacting professional-audio studio.

I found one dissenting voice in Paul Mirkovich, on the road as Cher's musical director for the past year. Mirkovich expressed wariness at using a rig that depends on software alone, and wasn't about to rearrange all his gear in the middle of a long tour. But I got the distinct feeling it was only a matter of time before he, too, came over to the software side. He hasn't replaced his Kurzweil setup with a laptop yet, but he did use Retro AS-1 on the tour as an additional sonic layer, producing percussive analog sounds and adding depth to pads. In fact, he already plans to build a show for Jeffrey Osborne using laptops to avoid the pitfalls of rental gear, although he prefers to bring along at least one keyboard that actually makes sound on its own.

PREPARE TO BE PROPELLED Rodney Orpheus, of the band Cassandra Complex, also uses just a keyboard controller and G3 PowerBook setup to produce industrial dance-oriented music. The Swedish software company Propellerheads-renowned in electronica and techno genres for its ReBirth virtual synth and ReCycle audio-processing software-makes Reason, Orpheus's chosen virtual synthesizer and effects system. Reason (in beta) is a digital implementation of a rack full of gear, complete with knobs, dials, switches, and rack-mount screws. You can even turn the whole thing around and make connections in the back with virtual patch cords.

Orpheus, who is also the Internet systems director at Steinberg, runs that company's Cubase VST/24 sequencer with lots of virtual instrument plug-ins installed. These include the LM-4 drum machine, VB-1 bass guitar, Model-E analog synth, Waldorf's PPG wavetable synth, and a digital re-creation of the classic Sequential Circuits Prophet-5 synth. "We've sold most of our hardware," said Orpheus-hardly a surprise, given all this sound-producing software.

HIGH-TECH GARAGE BANDS Of course, you don't have to be on the road with a big-name recording artist to use a computer onstage. Laptops are so cheap and powerful these days-and so ubiquitous in an Internet-connected world-that many musicians are taking them to local gigs routinely. Chris Burke of Bong+Dern, a New York-based music and sound design company, plays in a band called Tawney Pippett. Burke uses an Apple iBook in addition to an Ensoniq EPS16+ sampler to create electronic structured improvisations.

Says Burke, "I'd been doing everything with the EPS for a long time, but rather than figure out clever ways to load up multisampled instruments, I thought, 'Why not do the voice samples and the long evolving loops on the iBook?'" He uses a shareware program called SpongeFork to trigger AIFF files, and Hyperprism from Arboretum Systems to change the timbre and character of his samples in real time. Hyperprism's gestural BlueWindow control interface (which allows users to control multiple effects parameters in real time by simply moving the mouse around) provides him with the ability to perform live audio transformations he'd find difficult to manage on a more traditional sampler. "It's replacing things I would normally have done on the EPS and making my job easier."

Burke uses the laptop as an additional digital instrument, unconnected to his other gear. Om, keyboardist for Lost at Last, an "ethno-techno-tribal-trance-dance-chants" band based in Hawaii, takes the opposite approach. He brings an entire MIDI studio to the gig and uses his G3 PowerBook as the nerve center of the operation (see photo on p. 50). His eclectic setup consists of keyboards (Clavia NordLead, Yamaha CS1X, Kurzweil K2000), rack modules (Roland JV1080 synth, E-mu sampler), and a MOTU MIDI Express interface, all connected via serial and MIDI cables . . . not to mention a dulcimer!

This is a lot of gear to carry around, and Om certainly couldn't do it if he also had to lug a desktop machine and monitor to the nightclub. "Because of the kind of music we do, I have to be able to run sequences onstage, which means I need a sequencer of some kind, and nothing beats a laptop for ease of programming and for power," he says. After producing all the songs in advance with Emagic's Logic Audio sequencing program, he maps the sequences to notes on one of his controller keyboards, using a feature called Touch Tracks. That way, during a performance, he can fire off any given sequence at will while using his other keyboard controller to play the synthesizers; the computer automatically sets patch parameters for the latter.

Despite the complicated setup, Om has never had any trouble with the system at a show, though he does keep all the data backed up on Zip disks and runs the whole setup through an uninterruptible power supply. He'd prefer to make his rig more compact, but says he will always lug hardware to the gig because he likes to "tweak the knobs and buttons" during live performance.

ABSTRACT MUSIC In a more experimental vein, I attended a new-music concert in San Francisco that featured Tim Perkis on an electronic instrument of his own design, along with Electronic Musician associate editor Gino Robair and composer Tom Nunn on a variety of odd homemade percussion instruments. Perkis is a legend, in part because he's been performing in the computer-music genre since the early 1980s. Starting out with a Radio Shack TRS80, a digital-to-analog converter, and a Buchla synthesizer, Perkis built a device he calls a "mouse-guitar" that let him select notes on a fretboard and control other parameters by strumming the mouse.

Perkis now plays what he calls a "touch typing" instrument, which evolved from its Buchla beginnings into its current configuration circa 1991. It consists of a stack of three hardware components: a Kawai MIDI fader box, an ancient Toshiba T1100 laptop computer, and a Yamaha TX81Z synth module, all connected with a one-in, one-out MIDI interface (see Fig. 2). He also runs the audio output of the synth through volume and wah-wah pedals. Although underpowered by today's standards (with an Intel 8088 CPU at 4.7 MHz and only 400 K of RAM), the computer nonetheless runs a program written in C code by Perkis and produces a wide range of gurgles, screeches, drones, chirps, and other sounds.

Perkis plays the instrument by typing on the computer console and moving the MIDI faders. Each key on the console represents what he calls a blob or gene of data that programs a patch on the TX81Z. Each time he presses a key with Caps Lock down, the patch parameters mutate, generating a new sound. The MIDI faders work in pairs and set the upper and lower limits for various parameters, such as LFO rate, pitch, and ADSR envelope. He has designed the instrument to produce sound in an evolutionary and somewhat unpredictable manner.

"What's interesting about it for me is that it's kind of like playing with a person, in the sense that you don't really know exactly what it's going to do. . . . It has some of that improvisational quality even when just playing solo," Perkis says. "This particular instrument got frozen at a certain point, when I decided, 'Okay, this is it. This is what it does and now I'm going to learn to play it.'"

Perkis has no problem using the MIDI faders during performance: "There is something to be said for having a stable interface. . . . Sliders are underrated because they're kind of boring, but in fact they're great controllers because they stay exactly where you put them." However, precise control isn't necessarily the point of the operation; it's more about "defining an instrument and using the computer to give you a source of uncertainty and surprise, a lifelike quality to the music, allowing you to hear things you didn't really preplan," says Perkis.

The touch-typing instrument isn't the only laptop Perkis uses for performances. As a founding member of an ongoing project called the Hub, he has wired various laptops together to connect separate computer-controlled music systems into a network. According to Perkis, "Composers design pieces for the network by specifying certain properties of the data for exchange between players but leaving implementation details up to the individuals. The players then write computer programs that make musical decisions in response to messages from the other computers in the network. The result is a kind of enhanced improvisation."

Also on the concert program was another member of the Hub, composer Chris Brown of Mills College, who uses a G3 PowerBook and an arcane program called SuperCollider to produce his own style of abstract music. Basically, SuperCollider is a software synthesizer with an extraordinarily large number of parameters. While it's possible to manage settings via standard Macintosh window controls, mostly the player produces sounds using a programming language that resembles C code. SuperCollider is deep, powerful, and very complex technically.

CLOWNING AROUND One of the greatest advantages of using computer-generated audio instead of sequential tape in a live situation is the ability to access any sound on disk quickly in response to onstage events. I discovered this for myself in the fall of 1996, when I provided music and sound effects for "Pino Stands Alone," a one-woman show performed in San Francisco by Diane Wasnak-aka Pino the Clown, of the Pickle Family Circus.

The show called for an array of bizarre sound effects, played in response to Pino's acrobatic comedy sketches. These ranged from maniacal giggles and pig squeals to fly buzzes, cow stampedes, and a sneeze that turned into a magical whirlwind. In addition to original and improvised piano compositions, I also provided looped snippets of tunes by James Brown and Esquivel to accompany some of the acts. I converted the CD tracks into QuickTime movies that would loop until the scene ended. I made the sound effects into Macintosh resources and controlled them via a software interface called StageHand, a utility by Steve Hales that employs an early version of the Beatnik technology.

I rented a Macintosh PowerBook and loaded the audio files onto the laptop, using an adapter to take the stereo minijack audio output into my stage amplifier and from there into the house mains through a direct box. Pressing numbers on the PowerBook's keypad let me trigger the sounds at will while watching Pino's antics, between bouts of playing the piano. I had to keep track of a fairly complicated set of variables, but the laptop made it easy to set up audio for the eight scenes in advance and fire off effects when necessary.

AN APPLE A DAY Almost without exception, everyone I talked to uses Apple Macintosh laptops for onstage work-despite the wealth of inexpensive music and audio systems currently available for Windows. This makes sense when you consider that computer makers often regard audio cards as unnecessary for a PC laptop's primary purpose-business applications. On the other hand, Apple has designed the 16-bit, 44.1 kHz stereo sound built into every PowerBook model to support the production efforts of many creative Macintosh users. Even Tim Perkis describes his DOS-based Toshiba as more of an embedded processor than a multipurpose computer; his other laptop is a G3 PowerBook.

I did find it surprising that all of the players simply take the audio output from the minijack in the back of the Mac and plug it straight into the house with a direct box. Apparently, the Mac OS audio engine and digital-to-analog converters in the newer laptops are more than up to the task of delivering signals clean and clear enough for stadium audiences, television broadcasts, and recording studios. "We had companies telling us, 'You can't run SoundManager [the Mac's built-in audio],'" keyboard technician David Hampton recalls. "But when the audience stands up and cheers, it just proves what you can and can't do!"

Sometimes Hampton adds an inexpensive hum eliminator to the audio-output line, but generally it's not an issue. Harry Sharpe considered installing a digital audio card from Digigram with S/PDIF output into his laptop, but found the latency too great for live performances and decided against it since the analog output worked fine. However, almost no one was attempting to run both sample playback and MIDI sequencing software simultaneously; they apparently considered this too much for most systems to handle reliably in critical live situations.

Despite the usual software glitches and hardware incompatibilities that plague all computer systems, everyone I spoke to praised their laptops. They also had one common complaint-that the power cord would sometimes disconnect accidentally, leaving them running on battery power without realizing it. Usually, they detected the error and plugged the computer back in before the screen went dead in the middle of a song. But the worst potential for disaster is the stereo minijack connection, which is often less than completely secure. If that gets bumped loose during a performance, it can make an ear-shattering +115 dB noise . . . oops!

INDEPENDENCE DAY After researching this article, I'm starting to feel a little like Will Smith in Independence Day piloting the flying saucer and saying, "I have got to get me one of these!" I'd like to be able to expand my tonal palette in my own live setup beyond a piano and Hammond XB-2, but I'm definitely getting too old to carry around more gear. By using the "one keyboard and a laptop" approach, it seems, I could have a universe of professional and custom sounds at my fingertips while lightening my load considerably. It sounds so tempting; who knows, it might only be a matter of time before I, too, start bringing a laptop onstage.

Peter Drescher is a piano player, a composer, and the owner of Twittering Machine, a project studio in San Francisco. Special thanks to Andre Rocke, Lauraine Bacon, Willy Henshall, Gino Robair, and everyone else who contributed to this article.