Ideas are weapons in the war of careers, and their end result is ideology, not art. Those 88 notes are my Walden. For Feldman, the image replaced the idea. The length of his late works, two to six hours nonstop, intended to entice you to live with the music the way you live with a painting on your wall, slowly acclimatizing yourself to its implied universe. This isn't to say that Feldman tried to compose like a painter, for the reliance on images also comes from Stravinsky.
Construction is kept at a minimum.
But we miss Feldman's significance altogether if we don't see that the most important thing he brought back from painting was the artist's attitude of subjective immediacy in an era in which composers had become theorists and technicians. Watching Pollock and Guston on one hand, and his Europe-certified composer colleagues on the other, he came to contrast the dangerous and vulnerable life of the artist with the safe, justifiable career of the professional composer. In music, when you do something new, something original, you're an amateur. Your imitators - these are the professionals. Feldman became the Great One by imprinting young composers with the attitude of the artist, while everyone else was role-playing.