Vanilla is a product of Lussumo:
Documentation and Support.
For sheer weirdness, STIMMUNG, by Stockhausen, is pretty out there. It's all vocal, all dissonant, and stretches the human voice very, very far. Stockhausnen based it on 50-some "magic words", which are stated in an order to be dertermined by the players, and with great emphasis and intent. Moving through all these words takes about an hour, and is overwhelmingly surreal.