It looks like you’re looking for a PDF of Franz Wilhelm Ferling’s Grande Polonaise, Op. 12 (often referred to as the "Böhm Grand Polonaise" because it was written for Theobald Böhm’s new flute mechanism).
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Boehm was a master of acoustics. However, many editions of the Grand Polonaise include "harmonic fingerings" or "echo tones." boehm grand polonaise flute pdf
There are two primary versions of the score, both often available as digital or physical prints: Op. 16[a] (1831)
Libraries and Archives with Physical Collections: If you have access to a music library or a university library with a music department, they might have physical copies of the sheet music you're looking for. It looks like you’re looking for a PDF
Because Theobald Boehm’s works are in the public domain (in the USA, Canada, Europe, and Australia), you can legally download a free PDF—provided you know where to look. Do not pay for a "rare" PDF on eBay or random sheet music stores. Instead, use these reputable digital libraries.
Community Scores: A notation-software version is available on MuseScore for printing or MIDI playback. Technical Challenges (What to Look for in the
Dedications: Boehm dedicated the work to Paul Hippolyte Camus, a prominent French flutist and his business representative, who later wrote the first method book for the "Boehm system" flute. Where to Find the PDF Score
Opus 16[b] (c. 1842): A condensed version published in Paris with 314 bars. It omits about 100 bars and includes modified passages likely made by Boehm himself to heighten the work's brilliance. The work typically consists of: