When you buy an mp3, it should have a cable to hook to the computer. This is how you copy the music to the mp3, and may also be used to connect to a radio or speaker, provided the radio or speaker accepts the connection cable. Check your radio and or Bose to see what extra connection points it has. I have a Sansa mp3 that connects to a Timex radio, and the connection cable plugs into the earphone port on the mp3, thus allowing me to hear the music thru the Timex radio speakers.
I also bought a small speaker set, runs on two AA batteries, that are external speakers for an mp3. Also plugs into earphone port on mp3. Check radio and bose, see what you can find for hooking up mp3 to them. Good luck.

Thank you very much for your information. I have tried a couple of cheap mp3's because I like the idea of the battery being so easily replaced and no need to charge it. Unfortunately they just don't work so I'm going to return the second one and try something else. The problem they have is getting hung up on one song, not turning off when I switch them off, not playing some of the songs that I have downloaded. I am probably still doing something wrong but am just too frustrated with them for now. Anyway I appreciate you help - I will probably try something more expensive and see how that goes.