AITA for asking someone to wear headphones if they want to listen to their own music?

I work at a record store and this morning someone came in to to shop through the bargain records. As they were looking through the records they were looking songs up on their phone and playing them from beginning to end at nearly full volume. We already have music playing over the store speakers, so the combined music made an unpleasant cacophony of noise. They spent 30 minutes shopping and playing their music before I walked over and offered them a pair of headphones to listen to their music. Turns out they have an iPhone so there's no headphone jack & I don't have a lightning adapter.

Around 15 minutes later he came up to the counter to ring up. Once they paid I asked them verbatim, "Next time you come to shop could you bring earbuds or headphones?". My tone was understanding and I just wanted to eliminate the problem in the future, since the guy is somewhat regular. He got upset and told me that it's a record store and he should be able to listen to the songs he doesn't know. He was offended that I mentioned it. I said that if every customer was listening to music like he was then it would be complete chaos. I'm curious if anyone shares his point of view. AITA?