MOLA Errata List —maintained by the Major Orchestra Librarians' Association (MOLA)
—is a critical professional resource that documents thousands of musical errors found in printed orchestral scores and parts. Rather than being a single document, it is a vast, evolving database containing over 1,000 specific lists that help librarians and conductors correct inaccuracies before they reach the rehearsal stage. The Role of MOLA Errata Lists
Music publication is notoriously prone to human error. Even "definitive" editions of masterpieces, such as Beethoven’s symphonies, often contain incorrect notes, missing articulations, or rhythmic discrepancies. In a professional setting, these errors are more than just academic concerns—they can waste expensive rehearsal time and disrupt the creative flow of a conductor and ensemble. Key aspects of the MOLA Errata List include: Detailed Cataloging
: Each entry typically identifies the composer, work, movement, measure number, and instrument, followed by the specific correction (e.g., "F-flat s/r F-natural"). Urgency Codes
: Lists often use status codes to denote priority, such as "Critical" (would stop a rehearsal) or "Necessary" (should be done prior to performance). Global Pooling of Information : The database functions as a shared repository for MOLA members
worldwide, allowing a librarian in London to benefit from corrections discovered by a peer in New York. Importance in Performance Librarianship
For the orchestra librarian, the MOLA database is a tool for "editorial triage". By consulting these lists, a librarian can proactively mark corrections into a set of rented or owned parts, ensuring the musicians have the most accurate material possible.
While many individual errata lists are available through scholarly journals like the Journal of the Conductors Guild or specialized groups like the Orchestra Librarians Information (OLI)
, the MOLA database remains the most comprehensive centralized resource for the profession. during the part-preparation process? About - MOLA - Major Orchestra Librarians' Association
The MOLA Errata List (or Database) is a massive, specialized resource maintained by the Major Orchestra Librarians' Association (MOLA). It catalogs errors found in published orchestral scores and parts—including wrong notes, rhythms, dynamics, and articulations—to help librarians and conductors correct music before it reaches the musicians' stands. Key Features and Purpose
Massive Scope: The database currently lists thousands of corrections for hundreds of titles in the symphonic repertoire.
Efficiency: Using these lists saves significant rehearsal time by allowing librarians to correct errors in advance rather than identifying them during expensive ensemble time.
Member-Driven: Corrections are submitted and reviewed by professional orchestra librarians globally. Mola Errata List
Standards: The MOLA Errata Committee oversees the database, establishing uniform standards for submission and proofreading. Access and Availability About - MOLA - Major Orchestra Librarians' Association
The Silent Guardian of the Score: The MOLA Errata List In the world of orchestral performance, the distance between a masterpiece and a catastrophe is often just a single misplaced ink stroke. For the audience, the music of Mahler, Stravinsky, or Beethoven feels like a timeless, immutable force. However, for the musicians on stage and the librarians behind the scenes, a musical score is a living document, prone to the same human errors as any complex manuscript. At the center of the effort to ensure "perfect" performances stands the Major Orchestra Librarians' Association (MOLA) and its most essential resource: the MOLA Errata List The Origin of the Errata List
Musical notation is incredibly dense. A full symphonic score contains thousands of individual instructions regarding pitch, rhythm, dynamics, and articulation. Despite the best efforts of world-class publishers, errors are inevitable. A missed accidental in a trumpet part or a wrong clef in the violas can derail a rehearsal, wasting precious (and expensive) time. Major Orchestra Librarians' Association (MOLA)
, founded in 1983, recognized that orchestral librarians across the globe were independently discovering the same mistakes in the same editions. To prevent this duplication of effort, MOLA began compiling a centralized "Errata List"—a definitive catalog of known errors in standard orchestral repertoire. A Tool for Precision and Efficiency
The MOLA Errata List is more than just a list of typos; it is a critical tool for performance preparation. When a librarian prepares a "set" (the individual parts for every musician), they do not simply hand out the music. They must first "proof" it. According to professional resources like the Manual for the Performance Library
, using a MOLA errata list is one of the fastest and most reliable ways to check for major discrepancies without a note-by-note proofing of every single part. Librarians use these lists to: Correct Pitches and Rhythms:
Ensuring the notes on the page match the composer's original intent. Synchronize Rehearsal Numbers:
Preventing the confusion of a conductor asking for "Letter C" only to find it is in a different place in the woodwind parts. Standardize Articulations:
Ensuring the phrasing is consistent across the entire string section. The Collaborative Spirit of Music
What makes the MOLA Errata List unique is its collaborative nature. It is a living database built on the collective intelligence of the world’s most prestigious musical institutions. When a librarian at the Berlin Philharmonic or the Chicago Symphony identifies a new error in a contemporary work, like Aaron Copland's The Red Pony , they contribute that finding to the community.
This spirit of sharing ensures that a small community orchestra has access to the same high-level editorial corrections as a world-renowned ensemble. It democratizes musical excellence, ensuring that the integrity of the composer's voice is preserved regardless of the venue. Conclusion
The MOLA Errata List is a testament to the invisible labor that sustains the performing arts. While the conductor takes the bow and the soloists receive the applause, the quiet diligence of the orchestral librarian—armed with a red pencil and a MOLA list—ensures that the music played is the music intended. In an art form defined by precision, the Errata List is the ultimate safeguard against the chaos of the "wrong note." specific example of a famous error found in a major orchestral work? MOLA Errata List —maintained by the Major Orchestra
The air in the scriptorium smelled of ozone, old vellum, and the distinct, metallic tang of a reality that had been edited too many times.
Jory wiped the ink from his fingers—ink that was less pigment and more liquefied shadow—and stared at the ledger before him. The book was bound in the skin of a beast that no longer existed, a creature erased from the timeline three centuries ago. On the cover, embossed in fading gold leaf, were the words: Mola Errata List.
"Mola" was an ancient word, a remnant of the First Language. It translated roughly to "millstone," but in the context of the Guild of Rectifiers, it meant "The Weight."
Jory was a Third-Class Rectifier. His job was simple: the universe made mistakes, and he corrected them. He checked the List.
"Item 4,091," Jory muttered, reading the spidery handwriting that had manifested on the page that morning. "Location: The Kingdom of Orey. Error: The sun failed to rise. Correction: Insert Class-4 Stellar Ignition agent."
He sighed, dipping his quill into the shadow-ink. He ticked the box. Outside the high window of the tower, the sky flickered. For a brief second, the darkness turned a bruised purple, then blinding white. A new sun roared into existence over Orey.
Down in the manuscript, a new line of text bled through the parchment, fresh and wet.
Result: Successful. Crops incinerated. Adjusting.
Jory frowned. "Incinerated?" He tapped the page. "That wasn't supposed to happen."
The ink swirled, forming a response that hadn't been there a second ago. Correction to the Correction: The sun was positioned 0.04 degrees too close. Error acknowledged.
This was the danger of the Mola Errata List. It wasn't just a log; it was a conversation with a sentient, bureaucratic universe. And the universe was a terrible editor.
"Jory," a voice cracked from the doorway. It was Elara, an Apprentice, her face pale. "We have a bleed-over in Sector 7." Erratum ID: MOLA-2024-008 Location: p
Jory didn't look up. "Is it the dragons again? I told them to remove the wingspan parameters."
"No, sir. It’s a... narrative bleed. Someone is editing the List."
Jory froze. The quill dripped a blob of darkness onto the floor, where it hissed and ate through the stone. Only the Grand Rectifiers could write on the List. To edit the List itself was to put a knife to the throat of causality.
He stood up, his chair scraping loudly against the silence. "Show me."
They ran through the corridors of the Spire, past shelves containing the biographies of every soul who had ever lived—most of them dusty, some of them smoldering. When they reached the Observation Deck, Jory looked down at the world below.
It was... wrong.
A mountain range in the north had been replaced by a vast, bottomless ocean. In the south
These are not errors in the text, but rather rules that are frequently misinterpreted or missed entirely during initial playthroughs.
Erratum ID: MOLA-2024-008
Location: p. 117, Table 4.2, row 3, column “Dosage (mg/kg)”
Error: 0.5
Correction: 0.05
Date Issued: 2024-11-10
Notes: The original value exceeded the safe limit for murine subjects. All subsequent references should use 0.05 mg/kg.
When the top layer is pulled too tight by the presser foot, the fabric “tunnels”—creating a raised ridge of un-stitched material between parallel cuts. Collectors look for flat panels. If a mola has tunneling longer than 1 inch, it appears on the Errata List as a visual obstruction.
# Mola Errata List
## MOLA-ERR-XXX — Short title
- Version / Section: 1.2 — 4.3.1
- Type: Bug
- Reported Date: 2026-03-15
- Reported By: Example Org
- Description: ...
- Impact: ...
- Proposed Correction: ...
- Status: Proposed
- Resolution Date:
- Notes:
If you want, I can: