The song “Mr. Tambourine Man” was, of course, chiefly about drugs. He would have brought excitement and opportunities for enlightenment and spiritual growth.
Yet as rock and roll and, later, drugs lost their novelty, I’m sure the tambourine and its wielders had become quite passé. The role was surely doled out to those who had nothing else to contribute to a song. Maybe they contributed in other songs (like Clarence Clemens with Springsteen), were being sympathetically treated as obsolete has-beens (like Pigpen by the Dead), or were using their sex appeal to either titillate the audience or sleep with the boss (see Springsteen again).
“Hey! Tambourine guy, could you play me a song? Ha; just kidding! Go get me a beer when you’re done cleaning my toilet.”
A far cry from the tambourine player’s halycon days: