Delirium in Hi-Fi. Weird, wild stuff.
Almost everyone is familiar with the “Dawn” segment of “Spake also Zarathustra”, but the portions following it are intended to portray mankind wandering about in search of knowlege and enlightenment.
Depending on your desire, this might be appropriate for insanity of the type exemplified by the Three Stoges quote “I’m tryin’a think … and nuthin’ happens!”
Aha! I knew I was forgetting one…Liszt’s Totentanz, a series of variations on the Dies Irae chant.
Sections of this piece sound appropriately frantic and/or spooky enough, I think.
Charles Ives: Three Quarter Tone Piano Pieces, written 1923–24.