The general concept of "bageling" involves someone who isn't obviously Jewish looking identifying themselves to someone who is, not by saying "I'm Jewish too", but rather, by casually dropping a cultural signifier into their approach. For example, saying "boy, that bagel I ate for breakfast hit the spot", "do you know where I can find a good feli around here?" or "Shabbat Shalom" (on a Tuesday). I've noticed a similar musician-specific dynamic as well, particularly in the Yeshivish world..
A few recent examples:
1)
Me: <setting up to play a Bar Mitzvah breakfast at a Yeshiva>
Rebbi 1 to Rebbe 2 commenting loudly in front of me about my gear: RCF, pssshhh, they make the best speakers... etc.
2)
Guy in store who'd clearly been at the public concert I'd played down the road: "You have a 4X?"
Me: A 5X, actually.
Guy: "No one in Lakewood is using those yet."
3)
Guy: <places two-year-old on stage post-show while we are obviously breaking down the gear>
Me: Please take him off the stage, I don't want him to get hurt.
Guy: "It's ok. He knows how to behave around music and sound gear."
People, how about being normal and just saying "Hi! My name is x and I play x?"
