Actually, all the sounds were made by the artist! (although I think some synth was used on some vocals tracks). Wikipedia has a nice discussion of "A cappella" mentioning the modern trend of instrument emulation. Check out some of the vids at the SoJam festival site, some nice examples there. I like the editing also, reminds me of some stuff DJ Shadow experimented with at his NYC Roseland show for the Private Press tour. Neat to see the tech at the DIY level!