From Wikipedia, the free encyclopedia

A rehearsal letter is a boldface letter of the alphabet in an orchestral score, and its corresponding parts, that provides a convenient spot from which to resume rehearsal after a break. Rehearsal letters are most often used in scores of the Romantic era.

In the course of rehearsing a piece, it is often necessary to stop and go back to some point in the middle, in order to master the more difficult passages. Many scores and parts have bar numbers, every 5 or 10 bars, or at the beginning of each page or line. But as pieces and individual movements of works became longer as the Romantic era progressed, bar numbers became less practical in rehearsal.

For example, a conductor can tell his musicians to resume at bar 387, so that the musicians have to find bar 385 or 390 in their parts and count back or forward a couple of measures. Even if the number 387 is written at the appropriate bar, it might not particularly stand out. But if there is, for example, a big, bold letter M in the score and parts, it's much easier for the conductor to just say "letter M." Even if the conductor were to say "one bar before letter M," that would still be more convenient than saying "bar 386."

In the score, rehearsal letters are typically placed over the flutes' (or piccolo) staff, and duplicated above the first violins' staff (rehearsal letters should appear in every part). For typical pieces or movements of the Romantic era marked allegro, the letters A to Z can be used up, though the letter I or J (or both) may be skipped. For slow movements, approximately the first half of the alphabet might suffice.

The letter A is almost always used for a point close to the beginning, but not for the very beginning itself because it is much easier to say "from the top" or "start over." Likewise, rehearsal letters are not necessary at tempo changes. For example, in some editions of Beethoven's Ninth Symphony, letter A of the Finale does not occur until bar 140, when the relatively late entry of the first violins with the "Ode to Joy" theme might not stand out enough to the other players to be a convenient point of reference, whereas the reminiscences of the previous movements are more easily referenced by their tempi than by either bar number or rehearsal letter.

In some cases, A to Z might not be enough. After Z, Aa may be used, followed by Bb, and so on until Zz (though Ii and/or Jj might also be skipped). But in the case of some composers, such as Gustav Mahler and Dmitri Shostakovich, twice through the alphabet might still not be enough. Mahler's and Shostakovich's scores use rehearsal numbers rather than letters. These are typically in bold and enclosed in a box, or less commonly, a circle. Confusingly, however, some editions enclose bar numbers in boxes, though they're usually not boldface.

For this reason, some editors prefer rehearsal letters to rehearsal numbers. Advocates of rehearsal numbers counter that even 26 letters are not enough for some scores. Whereas rehearsal letters "reset" for each movement of a multi-movement work (even for connected movements), rehearsal numbers typically run over the course of the entire work, even if the movements are not connected. For example, the rehearsal number for the last few bars of the first movement of Edward Elgar's First Symphony is 55; the first rehearsal number of the second movement is 56.

There are exceptions, however. The final outburst in the first movement of Mahler's Second Symphony is rehearsal number 27. Mahler actually wanted a pause of five minutes before the next movement, so the rehearsal numbers reset to 1, ending with 15. The third movement follows after a short break, but its first rehearsal number is 28.

A rehearsal letter usually breaks a multimeasure rest in a part, except of course in cases where a given instrument does not play at all in a given movement of the work.

Because rehearsal letters are independent of edition and in some cases even version, they are also useful for telling applicants for positions in the orchestra what passages they need to play at the audition. And they are also useful for easy reference in scholarly essays about orchestral works.

Rehearsal letters might be used in chamber ensemble music, but they would have very little point in unaccompanied instrumental music (such as the solo piano repertoire), since the instrumentalist wouldn't need to communicate to a fellow player where to resume playing. For songs, it is more useful to refer to the lyrics of the song to indicate where to resume rehearsal (except of course in songs where the lyrics consist of a single word or phrase repeated dozens of times).

The Finale notation program by default provides rehearsal letters A, B, C and D. While it's capable of putting them in the score, it is incapable of renumbering or relettering if a large portion of the music is cut.

• Kent Kennan & Donald Grantham, The Technique of Orchestration, Sixth Edition.
• Gardner Read, Music Notation: A Manual Of Modern Practice.
• Kurt Stone, Music Notation In The Twentieth Century.