Jazz fans had just become accustomed to the replacement of "vibraphonist" by the term "mallet player" when along came "keyboard percussionist," an even broader category.

"It covers all the keyboard instruments," says David Samuels. "Not just vibraphone, marimba and xylophone, but bells, metallophones, bass marimba -- there's a whole family of them, an incredibly large family. In fact, the biggest keyboard percussion instrument of them all is the piano." Keyboard percussionists Samuels and David Friedman will perform in duo tomorrow night at Blues Alley, wielding their mallets on vibraphone and marimba.

"We've created this new format," says Samuels of their duo act. "We really have set a new precedent. And what's happened is that in colleges -- we both do a fair number of clinics -- it's not unusual now to see a vibraphone player and a marimba player playing together."

Samuels points out that, until several decades ago, jazz mallet players were a mere handful, "and there are not too many more of us now. They are slowly getting a little bit more exposure, but these are unfortunately still basically unknown instruments, not only with the public, but for a lot of musicians who don't get an opportunity to hear really good mallet players -- keyboard percussionists -- playing. One of the amazing statistics that I relate to people is that 95 pecent of people know who Lionel Hampton is -- but I'd say that only about 40 percent know what instrument he plays."