The New iPad: It's in the Apps - NYTimes.com: GarageBand, for example, has been blessed with several new music-making features. One of them lets up to four people play different instruments simultaneously. Somehow, their four touchscreen devices stay synchronized over Wi-Fi, and they make a master, perfectly synced four-track recording, ready for mixing, editing (there’s a new note-by-note editing mode) and posting online.