: Famous for being complex, his Symphony No. 9 has known errata where entire notes (like a Cello E-flat) must be manually changed by the librarian.
This is a catastrophic error: thread tension fails, and the bobbin thread loops into a tangled “nest” on the reverse. While many molas have messy backs, a true bird’s nest that distorts the front fabric’s flatness is an automatic reject for serious collections. Mola Errata List
: For a librarian, the "errata" (Latin for "errors") are a major time-sink. By consulting the MOLA lists, a librarian can proactively mark corrections into a set of parts before the first rehearsal. This prevents "stop-and-start" moments during expensive rehearsal time where conductors and musicians have to debate a specific note or dynamic. Community Knowledge Sharing : Famous for being complex, his Symphony No