Word!

Flea recorded the bass parts in The Mars Volta album De-Loused in the Comatorium, it is not an easy album to hear and not for everyone, very different to RHCP.

My two cents:  Pretty much every bass line off of Mother's Milk is GOLD.

I had no idea that Flea played on that Mars Volta album.  (And you're right, I can't listen to it).

Well I learned some new things here regarding RHCP, Mr. Bungle and Mars Volta.  Never listened to MV, but as far as concept albums go, far out (from Wiki):
 
De-Loused was a unified work of speculative fiction telling the first-person story of someone in a drug-induced coma, battling the evil side of his mind. Though lyrically obscure, The Mars Volta stated in interviews that the album's protagonist is based on their late friend Julio Venegas, or Cerpin Taxt, who was in a coma for several years. When he woke up, he jumped from the Mesa Street overpass onto Interstate-10 in El Paso during afternoon rush-hour traffic.