The One With the Male Nanny - S9-E6
Corrected entry: When Joey and Sandy are playing the recorders, the sound produced is out of sync with the finger movements, indicating that they are not actually playing the instruments.
The One With the Male Nanny - S9-E6
Corrected entry: As Chandler is leaving for Tulsa, he tells Monica to have Geoffrey (who Monica claimed was the funniest person she ever met) email him with funny Oklahoma jokes at www.hahanotsomuch.com. There is a real web page with this name with various quotations from that episode.
Correction: Not any more, I just tried.
Correction: No, their finger movements match the sound completely.