Question on phonemes

Okay, the r in my language seems to be turning out as /M\/, but it
might also be allophonically realized (is that right?) as a tap.  What
is the exact definition of a tap?  Are there examples in English or
French?  Thanks in advance...

--
Steve Kramer   -=oOo=-   scooter at buser dot net
Quote for the indeterminate time period:
"Did I do something wrong today, or has the world always been
like this, and I've been too wrapped up in myself to notice?"
= Arthur Dent, from _Hitchhiker's Guide to the Galaxy_