Baha'is do accept Qur'an as an authentic reporsitory of the Word of God and the BIble is viewed as being inspired... We're unsure though how authentic some of the more ancient religions actually reflected the revelation from their respective Prophets and Manifestations.
The Baha'is accept that Prophet Muhammad was as the Qur'anic verse revealed "Seal of the Prophets". Our explanation may differ however from the standard one accepted by most Muslims. We believe that the term "seal of the Prophets" means the Dispensation of Prophet Muhammad is the "Seal of the Age of Prophecy" and that this age ended in 1260 AH/1844 AD with the beginning of the AGe of Fulfillment of prophecy.
Others have suggested that the term Seal of the Prophets applied to Nabiyim or minor prophets receiving inspiration and not to Rasuli or Messengers of God that brought new dispensations, Holy Books and new ordinances, with authority to abrogate some of the previous dispensations.
An essay on this topic can be found at:
Baha'u'llah: The Great Announcement of the Qur'an
My own personal recommendation would be that we confine ourselves to Baha'i issues rather that argue about the place of music in Islam, that should be a topic for the Islamic board not the Baha'i board.
- Art