If your that concerned about noise and its a older building maybe your best bet would be to contact companies that blow in insulation and have insulation blown in to the space above the bars ceiling ( which would be the tenants floor ) then if you have insulation added to sound proof and have written into the lease that the tenant is fully aware they are renting a unit that is above a bar and that the unit has had sound proofing done between it and the bar and they should expect some noise at times that may disturb them like bar customers having disagreements outside or things like a car or taxi pulling up and honking and that there could be noises that still disturbing at times. LASTLY if your going to offer long term lease as in multiple months like a 6 month or a one year long lease then you may want to have a buy out clause listed in the lease that requires them to give you one rental period of notice ( why one rental period , because before they move in you want first month , last month and deposit all at once in cash and then if the person still claims its too noisy even with signing your disclosure they can forfeit the last months rent they paid to you ahead by giving one whole rental period so say you had a tenant who signed a 12 month lease and moved in 12/31/15 and then decided they cant handle the noise by Jan 10th , but your lease with them disclosed to them the nature of the business and made them aware of noise (even after you insulated for sound proofing ) and they wanted to leave right away , in order for you to agree to let them out of it early they would have to give you notice that they will vacate by the end of Feb and rent payment must be made with the written notice asking to terminate early ( even if you only showed that unit at night when the bar might be noisy this unit is in CA where it seems that landlord tenant legal issues can be more challenging to landlords so you may have to take more steps make it nearly impossible for a tenant to claim they didn't know, or that it was too noisy. OR to just keep it month to month and make sure they have paid the last month in advance AND don't let tenants be late with payment. NO grace period in lease , if rent is due on the first and they don't pay it don't waste time start the process to evict based on non pay.
