Though I feel the Tyros 4 includes a fantastic palette of terrific sounds, the advantage of purchasing the optional Yamaha FL 1024M or Yamaha FL 512M Flash Memory Expansion board is the ability to expand its impressive sound palette even further with Yamaha Premimum Voices, 3rd Party Voices from Orgel-Studio (Pemo) (btw: they just added a brand new 'Pack 9' , and other 3rd party vendors, or samples you might create yourself.

For Tyros 4 owners that don't have the optional Flash Memory Expansion Board (yet) here's a quick tutorial I found posted on YouTube recently on how to install to install the Memory Expansion Board:






On another note, congratulations to forum member buddy Nick Galea (Nick_G) who visited here in SF back in August, on his new Tyros 4 purchase yesterday.
I bet he got no sleep last night setting it up and playing it into the wee hours of this morning.

Still enjoying playing & exploring my Tyros 4 keyboard more than ever. - Scott