This music module has 4 channels of pattern data. Depending on the format used, more channels may be played simultaneously.

8580 signifies the MOS Technology 8580 sound chip, found in the Commodore 64 line of computers. 8580 is often referred to as the "new SID", since it was the second of two models - the 6581 preceded it in older models of the Commodore 64. More information at Wikipedia).

MOD is the tracked music format used by ProTracker and many compatible tracker applications. This tag also covers variants of the MOD format with identical file structure but more than four channels.