Bass Cafes. Yeah they exist-

So, the concept of a bass cafe is really simple. Its kinda like those NSFW places with the hot girls that do inappropriate dances or something. The visitor goes into a soundproofed room and sit with a blob who's attracted to bass and/or speakers (which, by the way, is not just Passo)* and put some music on for them to react to. There is a place to dock a PonPou, alongside various audio input jacks.

All seats have a speaker. Visitors usually purchase a medium sized plate of an appetizer, an appropriate serving for two visitors, typically advertised as enough for a couple. However, it is known that visitors will share the food with the blob they're seated with

Passo works at one located in the city under the name "Scarlet", and is one of his MANY occupations. Originally she did the typical: visitors would put on a tune and see her react. 

She currently brings her bass to play for visitors and encourages others to bring instruments to jam out, instead of helping him find new songs to lust over. Because of this, she's usually fully booked. She's got in contact with the other blobs to teach them how to play bass... turns out, some of the people in those rooms were already bassists. So if Scarlet's booked, then another can play the bass for people...