|Relative key||G minor|
|Parallel key||B? minor|
|Dominant key||F major|
|B?, C, D, E?, F, G, A|
Many transposing instruments are pitched in B-flat major, including the clarinet, trumpet, tenor saxophone, and soprano saxophone. As a result, B-flat major is a popular key for concert band compositions.
In Nordic, Baltic, Western and Southern Slavic (except Bulgarian) languages, Hungarian, German and most Central and Northern European languages, the pitch B is sometimes called "H" (while B-flat is called "B".)
Joseph Haydn's Symphony No. 98 is credited as the first symphony he (or anyone else) wrote in that key in which he included trumpet and timpani parts. Actually, his brother Michael Haydn had written one such symphony earlier, No. 36, though Joseph Haydn still gets credit for writing the timpani part at actual pitch with an F major key signature (instead of transposing with a C major key signature), a procedure that made sense since he limited that instrument to the tonic and dominant pitches. Many editions of the work, however, use no key signature and specify the instrument as "Timpani in B-flat-F".
Media related to B-flat major at Wikimedia Commons