I constantly am bombarded with genius ideas to songs, bass riffs etc. and as fast as they come, they go.. I was wondering if this field recorder would be the key to recording at least my singing and my mouth making a beat overlapping it. Is this just using 2 channels of the 4 in the Zoom H4n? Is that what a "channel" means? Do I only need a H2? Or perhaps is there a better technological device you guys could recommend? Also, is it possible to plug in my bass and headphones and record a bass riff then sing over it? etc. etc. Thanks!