Phil Kraus' Modern Mallet Method (Vol. 1, p.11) states (with illustration) that the correct placement of mallets is "left mallet above the right" (also sometimes called "stacked"). However, Buyer & Gottry in The Art of Vibraphone Playing emphasize striking the bar in the same place except, "in rare cases where rapid rhythmic figures or rolls are required on the same bar, the mallets should be off-set, with one mallet just above the center of the bar." Other method books I've inspected (e.g., G. H. Green, M. Goldenberg) don't remark on this one way or the other.
I'm certainly finding left-over-right to be both easier to control (i.e., avoiding mallet collisions). Also, I'm loathe to discount Kraus' explicit direction given his historical importance as a performer and instructor. However, given my comfort level with it I'm concerned that if left-over-right is not the preferred modern approach it will become an ingrained habit rather quickly and lead to problems later on. For those that have had the benefit of personal instruction (at this time I do not) what has been the received wisdom on this issue?
