Goodness. There are apps for everything these days. I’ve got a speaker that’s water proof for outdoor use and hooks up via blue tooth . All the music my husband downloaded I can listen to via my headset or this speaker. Unfortunately, his is a company computer and iPhone and they no longer let him do that.Unfortunately without a computer and internet access your options are quite limited. One possibility you might explore is to download a Karaoke app on your iphone. There are several available. Along with that you can purchase a speaker that works with apple airplay that you can listen to the music tracks and play or sing along. I am just a novice with all of this iphone mumbo jumbo, but I suspect there are other members with more experience who can offer more detail.
This speaker doesn’t look like much but it’s actually very good quality and has exceptional sound. Don’t let the size of it fool you.