programmable 16 step shift register?

[R.Fahl]

I'm looking for a way to make a simple 16 step sequencer that will simply
read button presses as ons and offs and repeat the sequence over and over
like a drum machine.  I want to be able to do "overdubs" on the fly, by
simply advancing the sequence of 16 with a new stream of pulses (shift
register styley).   I'd also like it to be cheap and simple to build, and
syncable so I can run several in parrallel.

I want it to be a tape loop and drum machine programmer in one.  ANy
feedback on how it could be done?


Also, has anyone experimented with using BBD delays for looping sequencer
CVs?  Someone I know has done this with a serge with a tkb and a wilson
analog delay.