The Sendai quake was the biggest on record for that region and the fifth largest ever in recorded history. What a mindboggling disaster of epic proportion and has been stated by experts as being hundreds of times more devastating than the recent Haiti earthquake, as far as property damage and sheer destruction are concerned.
Yamaha and Roland Japan are located about 350 miles to the southwest and have probably been left pretty much unscathed from this disaster, albeit, I have no way to determine that for certain unless someone from Roland or Yamaha were to chime in. Fat chance most likely. On the other hand, Korg is located in Toyko which is only 150 miles from the epicenter and they may have been severely affected by this quake. Again, no way of knowing for sure unless a representative from Korg were to chime in.
If you'd like to help out financially you can do so through the American Red Cross or some other reputable charity. Here's the American Red Cross website:
American Red CrossAll the best,
Mike