I believe the concept of triggering pre-recorded vocals via multi-pads is yet another live triggered tool to creatively enhance arranger keyboard performance.
I wouldn't do this for an entire show, but for a couple of select songs, it could really be a big hit.

I live in San Francisco where I'm always requested to perform "I Left My Heart In SF" (Tony Bennett), "SF Flowers In Your Hair" (Scott MacKenzie), and "Go West" (Village People/The Pet Shop Boys)
of which is universally recognized as sung by the above cited singers.

Hearing it sung by the original hit artist, yet me playing live
(piano) + auto accompaniment (drums & bass + strings) helps satisfy the audience's initial recognizable voice expectation, and then after 8 bars, I might introduce
my vocal rendition + play instrumental solos and then perhaps throw in some hints of the hit version singer's vocals (signature vocal rifts, etc) again to create a musical montage.

The ability to use multipads to trigger vocal audio to our arranger keyboard music can open up some interesting creative possibilities.
I've always wanted the opportunity to sing & play with some of the greatest singers & musicians of all time, so with 'vocal only' audio tracks now available commercially,
so perhaps now can "Play my Dream", or as Yamaha claims with Tyros4: "Hear the difference, play your dream"

I'm a fan of renowned saxophonist musician Dave Koz. wikipedia link

Here's an example of how Dave Koz got to perform on his Sax with Dean Martin in 2007 (twelve years after Dean Martin's passing).
I heard him do this at a live concert and everyone in the audience loved it.



Scott