The project for the new 3-manual Dobson organ at Merton College, Oxford was supervised by an AIOA-accredited adviser Because pipe organs are so long-lived, the need to commission a new one, or renovate an old one, doesn't arise very often.  But when it does, an adviser is required with answers to all the resulting musical, technical, acoustical, architectural and historical questions.   The Association of Independent Organ Advisers (AIOA) exists to provide and accredit these experienced specialists. 'Armchair knowledge is not enough!' they warn, and accredited members have to demonstrate a high level of skill and…