As countless bands release iPhone applications offering little more than a mobile version of their websites, electronic musician BT has a bigger goal. He wants to turn his phone into an instrument.

BT, along with a small team of developers at his company, Sonik Architects, built Sonifi, an iPhone app that lets users very easily manipulate songs on the fly.

Brian Transeau, best known by his stage name BT, scored the soundtracks to "The Fast and the Furious," "Zoolander" and "Go," in addition to gaining a significant underground following for his solo releases. His pioneering stutter sound effect influenced the trance genre.

A standard pop group's iPhone app offers little more than a band site, with music streaming, tour schedules, news and photos. MySpace's iLike built an entire business around it.

So, there's something to be said about a musician with a truly original utility. T-Pain has his Auto-Tune toy; Nine Inch Nails has its location-based Twitter app; and now, BT has Sonifi.

The app, available at the iTunes App Store, comes with just one song -- a dance track. But you can spend hours playing with it.

Karl Hyde of Underworld likes to talk — a lot.

“I see interviews as a fun part of the process,” he chuckles over the phone from England as Underworld prepares for a string of shows in America, including a headlining slot at this year’s edition of the HARD Summer festival at the Forum on Saturday night.

Indeed, spend a few moments talking with Hyde, and he will pontificate on various topics including “Doot Doot” -- the lone “hit” single from Freur, the ‘80s outfit he was in with fellow Underworld member Rick Smith -- and the unique way Underworld chooses which songs to play before a show.

“Rick and I get together with the crew," he says. "We have all of the song titles on individual laminated cards, which we deal out on the table. Rick turns to the crew, well, mostly to Haydn Cruickshank, our lighting guy, and asks what he wants to hear that night. And that’s where we start. The rest is up to the crowd.”

Hyde gets candid when asked about 1996, when Underworld’s song “Born Slippy” was famously used in the Danny Boyle film “Trainspotting” and went on to become a worldwide dance-floor smash.

“The Legendary Adventures of a Filter King” is the name of a forthcoming vinyl-only box set of tracks recorded by Detroit techno star Carl Craig under the moniker of 69.

Collecting the previously released singles “Sound on Sound,” “4 Jazz Funk Classics,” “Lite Music” and “Pungtang,” the first 100 copies of this limited run of only 500 box set also include a special 69 T-shirt designed by San Francisco’s Nice Collective.

These productions date from the early 1990s and find Craig mining all sorts of music for sample sources (“Rushed,” for instance, famously recycles a loop from obscure U.K. electronic act Bandulu’s “Amaranth -- Love Lies Bleeding” into a metallic techno march). The results run the gamut from dense dance floor workouts (“Jam The Box”) to moody and emotional electro-ballads (“Desire”).

Exclusive to the set are previously unreleased mixes of the songs “If Mojo Was A.M.” and “Poi et Pas.” Craig’s work as 69 still stands among his most exciting and inspired studio moments to date.