The iPhone's application capabilities continue to astound us. We've seen on-the-fly multitrack recording already in our a cappella review of Sonoma's 4Track app, but this one takes it to a whole new level. Voice band is a multitrack recording app that lets you build up the sound of a full band, including guitars, bass, drums, sax, synths and vocals, using only your voice as an input. The demo video after the jump shows just how simple this process is, and how astoundingly good the results are. Amazing stuff.

Voice band takes your voice as an input, and uses it essentially as a programming code for a bunch of different instrument sounds, which you can then layer up into a multi-track rock song.

Instruments include electric guitar, electric guitar power chords, bass, sax, 2 synths, drums and a basic recording mode to layer vocals on the top. There's multi-mode pitch correction, distortion, reverb and delay effects, plus an adjustable octave option and adjustable tempo. You can play along an MP3 from your iPod music library and sing over the top of it too, if you like.

Apparently there's a pro version coming out in the future that will output your vocal input tracks as MIDI. Now that's something any composer or arranger could make good use of. Excellent idea.

You have to wonder what Beethoven or Chopin would do with an iPhone... Although the sad truth is probably that they'd spend all day playing Bejeweled Blitz and stuffing about on Facebook like the rest of us.