I used to beat box into a cheap mike into my stereo using the cassette record function. It was a dual cassete deck and if I took my new beat box track and put it in the other cassette side and press play I could record a new track layered on the first one. The old track would loose just a little volume. I would do this like 50 times switching the 2 cassettes back an forth. It would actually sound pretty good.
