If there was so much damage, it sounds like they were negligent in how they went about the work. Ask the landlord to talk to the company who did the work. They may have insurance that will cover the damage. You can let the landlord know that if they don't, you will seek damages from him for the damage. Its better if he is motivated to try and get the contractor to pay for the damages they created.
Scott Rights, Esq.
Yes, you can sue. You didn't really describe how the piano and computers were damaged, but your uphill battle is to prove (1) causation, and (2) damages. Are these items repairable? Or a total loss? How will you prove value? Will you be able to explain to the judge how you would not have been damaged to the same extent if you have been given MORE than 48 hours notice?
The information presented here is general in nature and is not intended, nor should be construed, as legal advice. This posting does not create any attorney-client relationship with the author (who is only admitted to practice law in the State of California). For specific advice about your particular situation, consult your own attorney.