I fail to understand the relevance of the name or what the name is intended to signify.
What matters is that this place serves decent grub (local and western), reasonable price beer and has a pleasant atmosphere.
The place regularly hosts (several times a week) bands that appeal to the backpacker / ex-pat type crowd. Although most singers are Thai's who, are thus not singing in their own language. The standard is surprisingly high.
Dress Code: n/a
Post Laser Disc is another Hat Yai evening entertainment venue. There are quite a few places like this in town. Post Laser Disc makes a big thing out of the fact it is featured in Lonely Planet, which it is but don't let this put you off.
Dress Code: None
Hat Yai has it's fair share of live music, most of this is in the style of a thai band belting out western music.
There are several bars on the same strip as post laser disc that have live bands and they are all well worth a look (if you like that sort of thing). Post laser disc probably had the best when I was staying there, music started around 8 p.m. and went on until the early morning. The bar itself is typically cheap although it has that dark, grungy feel you get with most unsigned band haunts in the u.k.
Dress Code: No dress code of note
Have tried this place a couple of times now, and although a jug of Chang draft is 120 baht in happy hour, the food needs a lot of attention. I ordered the chicken kiev, and asked for it to be hot (it was cold last time) sure enough the kiev & fries were hot, but the veg was stone bonk cold. Portions also very small.
Cheap good food, Live music, friendly atmosphere and plenty of good beer - what could be better?
Dress Code: Informal as you like - I wore my dodgy hat all night!