BTL is the local ISP. You can setup an account with them by visiting their office in San Pedro and they will give you a booklet explaining how to connect to their server. The cost is $40BZ per month which includes 8 hours of connection and after that it is $6 per hour (or part hour). The cost of the call is free.
And on live music most of the bars have live music during the week, it is just a question of finding one to your taste !