Jeanie...My Dad did the same thing with his pipe against his teeth, I think subconsciously. I wonder if it's common among pipe smokers.

Recording sessions sometimes turn up some weird percussion things. Drum sounds can be hard to fine tune, so we once ended up with a piano stool covered in (I think) a cloth instead of a snare drum. Trouble was the drummer had to reposition the cloth throughout the recording while he played, without loosing the beat. He was brilliant.

We once had trouble getting the right bodhran sound so I ended up playing it between my knees with my hands, bongo style. Muting with alternate hands took some otherworldly concentration, but the sound was there.

We used to play Shule-a-roo (please forgive the spelling) with shaker, drum, guitar scratches, and best of all a tamborine rigged to the end of a stick the other end of which was beat on the floor. Two sounds in one from the stick rig.

Peace, Mooh.