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.