Uncle Dave, not only will you probably not see a Tyros on MTV, but I doubt you'll see any other arranger type keyboard (even with the larger keys) used in this type performance venue either. The reason is because they're 'arrangers', not because of the key size, as I've already spotted a 61 note Yamaha Motif6 (with PSR sized keys)being played on TV.

The simple fact appears (to me) that arranger keyboards are primarily utilized professionally by 'one man band' type solo performers, songwriting & studio production work.

Scott