Friday and Monday are both National Holidays...there should be plenty of partying from Thursday to Sunday night...and most of the day Monday...especially at the beaches.
If you want more North American-type music, go to the shopping plaza at Playa Dorada, there are several bars and dance clubs that will probably be packed every night...there's also a larger club in the complex called Spice ( i think...most people still call it Mangu)...you can walk between all the different places...