In the first movement of Merlin it is noted for each roll to be played as independent rolls. Are ripple rolls acceptable?

without a doubt... no. spend the time learning the correct technique slowly. the composer obviously knew exactly what he wanted... or he would not have specified anything at all. if you cheat with sloppy rolls, you are only hindering your own progress.

Micah,

From my understanding, being a student of a student of Nancy Zeltsman (whose recording and performance of the work, the composer has OK'd to the best of my knowledge): Ripple/normal rolls are fine. The reason for this is the independent roll cannot, with any grip, ever reach the volume and intensity required by this work. That said, it is possible (though I've never heard it done this way) that during the passages from approximately forte down to piano, one could feasibly execute independent rolls. I'm not sure that independent rolls do anything to enhance the music of Merlin, and may, indeed, detract from it.

My two cents,

mike