Gabriel & Dresden live @ spirit, 4files?

I downloaded this G&D set (took me about 6days, cause I'm still not connectable, I tryed opening up ports in my router, changing ports in Azureaus, but still nothing ). Now I wanne play this set but in the folder where I downloaded it there are 4 files. Can someone please tell me what the use of these files is. I hope someone can help me with this.

.m3u - winamp playlist
.nfo - some info
.sfv - nfo for the achive, i guess
.mp3 - you know what to do

are there problems playing the mp3 file?