For the distinguished professional Classical Concert artist… petosa first re-defined it’s Concert Series Converter Free-Bass with the addition of the Cathedral Bayan SV. Now petosa has advanced the SV model with new features and sound. The Cathedral Bayan SV Grand Concert begins with a solid-core Mahogany cabinet featuring 100% mahogany interior and petosa single piece solid mahogany tone chamber. Newly designed reed block construction optimizes air use, allowing for instant, distinct response and ultimate power. This exquisite build incorporates the highest standard Free-Bass mechanics for reliable durability, re-establishing the NEW Cathedral Bayan SV Grand Concert as a distinctively premiere Concert Bayan accordion for the most discriminating, professional musician.