Playing a round with the RC-50

["Andrew Koenig" <ark@acm.org>]

Well, I really mean singing a round.

One would think that there is an easy way to do this, but I can't find it.

Here's the problem:  I want to sing a round using the RC-50.  So I connect 
a
microphone to it, turn off the rhythm guide, put it in overdub mode, and
start singing the first part.

When I'm done, I want to start singing the second part along with the first
part.  But if I hit the record/play pedal, it puts me in play mode.  I have
to hit it twice to go into overdub, by which time I've lost tempo.

So how do I go about it without having to wait for the round to come around
again?