ID3 is a format for metadata in mp3 files, basically a string of numbers that translate into info such as artist, album, year etc. There’s also a number that signifies a specific genre (eg. 16 is reggae, 32 is classical, and so on).
But 108? That just means Primus.
All of this is just to say that Primus are such a unique beast that the numbering system for mp3 genres has a number just for Primus. No other band is afforded this honour.
You could label them as something alternative, maybe funky, but Primus are just Primus.
Primus are a three-piece, with a guitarist and drummer, but the central element is always going to be ringmaster Les Claypool and his bass. Colonel Claypool’s unique and elaborate playing style places the bass in a far more musical role than is traditional, and it’s an iconic element of the Primus sound.
That unique and innovative Primus sound gained them a huge following in the 90s alt metal scene, and they’ve toured alongside many big names. Yet Primus have always kept their iconic style. For over 35 years they’ve stayed true to themselves, and nobody else has dared try and emulate them.
Because you just can’t be a Primus clone without a Colonel Claypool.