PETROF opus numbers and piano age: identify the right instrument

For PETROF, the identifying number of an individual instrument may be called its opus number as well as its serial number. To use it for an age estimate, keep the number together with the complete brand name shown on the piano.

Which PETROF entry does this guide cover?

This guide concerns the entry identified in the Piano Atlas as “Petrof, Anton”. Its guidance does not automatically apply to similarly named results such as “PETROF, ANTONIN” or “Petrof, Josef”. Check the inscription on the instrument before selecting an entry: a similar name alone is not enough to establish which numbering context applies.

What is an opus number?

PETROF uses the term for an individual instrument’s identifying number. The manufacturer also uses it when providing information about Weinbach, Rösler and Scholze uprights and grands. A shared term does not establish a shared numbering sequence. For example, a Weinbach inscription should not be treated as PETROF merely because the number is described as an opus number. PETROF and opus numbers in the Piano Atlas.

The useful starting point is the combination of name and number: what name is written on the instrument, and which number identifies that instrument? Record both, rather than copying a string of digits on its own.

Record the complete number

You need the number of the upright or grand itself. A marking on its action or keyboard may refer to that component. Photograph the brand inscription and the number with enough surrounding detail to show where each was found.

Keep letters and leading zeros. If a character cannot be read, record the gap without filling it with a guessed digit. A year displayed on a medal is not a substitute for the factory number either. Help with component numbers and unreadable characters.

Using the opus number to estimate the production date

In the Atlas, select the entry that matches the full inscription and enter the number you have read. This guide is limited to “Petrof, Anton”; it does not transfer numbers from other results or brands into that entry.

A production year estimated from suitable comparison numbers is approximate. Missing characters or uncertain identification may limit the conclusion, so read the explanation accompanying the result. Without an identified instrument number, neither a company’s founding year nor a date on a component automatically gives the production year of the whole piano.

Look up PETROF in the Piano Atlas