Entertainment in Catemaco
Entertainment in Catemaco is basically of the
do-it-yourself kind.

Frequently the county government sponsors concerts
on the central plaza and usually some sort of fair is
going on either in Catemaco or the surrounding areas.

If you are desperate for music, many groups of
troubadours will sing most anything for a buck,
per musician, per song.

As for nightlife:
Latin culture stems back to the siesta days, when the
daily nap made it possible to start partying at midnight.  
Los Tuxtlas still maintains that attitude. So who are all
those people jogging the Malecon at 6 in the morning?
Catemaco nightlife centers around the center of
the Malecon which in the last few years has
converted itself into a miniature Zona Rosa without
the eateries. It features several open air discos
that you can probably hear in Mexico City.

The traffic is mostly crowds of teenyboppers from
neighboring cities on the weekends.

Check out 2 somewhat more adult places:
La Ostería - wine and beer cave
La Casa de Los Caballos - cantina & duck burgers
There is no official red zone (zona roja)  in Catemaco,
zona de tolerancia. It harbors multiple cantinas all
dealing in unofficial prostitution.

A friendly bar with a karaoke setup and a singing
owner is Cello's near the southend of the carretera.

Word of Caution: enter cautiously and get out at the
first sign of trouble. Gringos are fair game to any local
drunk, unless the management controls him.