E major is hard for wind instruments to play. It is quite good for violin, because two of the open strings are A and E, the tonic and subdominant. Other orchestral string instruments can play well in it, and it is also good for the guitar. When writing in E major, clarinets in A should be used instead of clarinets in B-flat to make it easier to play. This is because clarinets are transposing instruments.
Symphonies in E major are quite rare, but the key is often used for concertos. One of them is Felix Mendelssohn's Violin Concerto.
The bells of the Clock Tower in London's Palace of Westminster are tuned to the key of E major.
C-sharp minor
C-sharp minor or C minor is a minor scale based on C. Its key signature has four sharps.
Its relative major is E major, and its parallel major is C-sharp major.
There are very few symphonies written in this key. One of them is by Joseph Martin Kraus, but he later rewrote it in C minor. Another two are Mahler's Symphony No. 5 (though only the first movement is in C-sharp minor, and the finale is actually in D major) and Prokofiev's Symphony No. 7. Shostakovich's Violin Concerto No. 2 is also in C-sharp minor.
This key occurs more often in piano music. Domenico Scarlatti wrotetwo keyboard sonatas in C-sharp minor, K. 246 and K. 247. But after Beethoven's famous "Moonlight Sonata", the key became more popular for piano. Beethoven used this key again in the outer movements of his String Quartet No. 14 (Op. 131, 1826). However, Johannes Brahms rewrote his C-sharp minor Piano Quartet to be published as Piano Quartet No. 3 in C minor, Op. 60. One of the most famous pieces in this key is Chopin's "Fantaisie-Impromptu". Other works include Chopin's Nocturnes No. 7 (Op. 27, No. 1) and No. 20 (Op. posth.), and his "Raindrop" Prelude in D-flat major (Op. 28, No. 15). Waltz in C sharp minor (op.64 No.2) is another well known musical piece from Chopin that uses this particular key (along with D flat minor key). Another very famous example of a work in C sharp minor is Rachmaninoff's Prelude in C-sharp minor (Op. 3, No. 2).
B-flat minor
B minor or B-flat minor is a minor scale based on B-flat. Its key signature has five flats.
Its relative major is D-flat major, and its parallel major is B-flat major. Its enharmonic equivalent is A-sharp minor.
B-flat minor is often seen as a "dark" key." Tchaikovsky said that the oboe solo in B-flat minor in the second movement of his Symphony No. 4 was "the feeling that you get when you are all alone".
The old valveless horn could not play easily in B-flat minor. In fact, the only example found in 18th century music is a modulation in the first minuet of Franz Krommer's Concertino in D major, Opus 80.
B major
B major is a major scale based on B. Its key signature has five sharps.
B major's relative minor is G-sharp minor, its parallel minor is B minor, and its enharmonic equivalent is C-flat major.
The key signature for B major is the least sharp key signature with three "lines" of sharps. In the treble clef, putting the sharp for A where it looks like it should be, next to the sharp for G, would mean that a ledger line would have to be used. In the bass clef it would be possible to do this without a ledger line, but because sight reading is easier when both staves look the same, it is not usually done in piano music. In the alto clef, used in orchestral music, the B major key signature is usually written in just two "lines" of sharps.
Although B major is usually thought of as a "far away" key because it has many sharps and is quite far from C major in the circle of fifths, Frédéric Chopin thought that it was the easiest scale of all to play, as its black notes fit the natural positions of the fingers well. Because of this, it was often the first scale he taught to beginning piano students, leaving the scale of C major till last because he thought it was the hardest to play.
While B major is not too difficult to play on keyboard instruments and guitar, the key of C-flat major is easier when writing music for the harp, as it is that instrument's home key.
G-sharp minor
G-sharp minor is a minor scale based on G. For the harmonic minor, the F is raised to F.
Its key signature has five sharps.
Its relative major is B major.
The melodic and harmonic versions of the scale are written in with accidentals as necessary.
G-sharp minor is usually not used in orchestral music except to modulate, but it is more common in keyboard music, like Scriabin's sonatas. For orchestration of piano music (writing it so an orchestra can play it), sometimes the music is transposed to G minor or A minor. If G-sharp minor must be used, B-flat wind instruments should have their part written in B-flat minor, not A-sharp minor.
In a few scores, 5-sharp key signatures in the bass clef are written with the sharp for the A on the top line.
G-flat major
G-flat major is a major scale based on G-flat. Its key signature has six flats.
Its relative minor is E-flat minor, and its parallel minor is G-flat minor. This is usually replaced by F♯ minor because G♭ minor's two double-flats make it generally impractical to use.
Its enharmonic equivalent is F-sharp major, whose key signature also has six accidentals. In writing music in E major for B-flat instruments, it is preferable to use a G-flat rather an F-sharp key signature.
G-flat major is sometimes used as a main key for piano works, such as the impromptus of Chopin and Schubert, but rarely for orchestra.
Austrian composer Gustav Mahler liked to use G-flat major in his symphonies.
E-flat minor
E minor or E-flat minor is a minor scale based on E-flat. Its key signature has six flats.
Its relative major is G-flat major, and its parallel major is E-flat major. Its enharmonic equivalent is D-sharp minor.
This key is not used much in orchestral music, and usually only to modulate. It is used in some keyboard pieces and has been most popular in Russian pieces. If piano music in this key must be arranged for orchestra, some people recommend transposing it into D minor or E minor.
In book 1 of the "Well-Tempered Clavier" by Johann Sebastian Bach, Prelude No. 8 is written in E-flat minor while the following Fugue is written in D-sharp minor. In book 2, both movements are in D-sharp minor.
One of the few symphonies written in this key is Prokofiev's Symphony No. 6. A few other Soviet composers also wrote symphonies in this key, such as Eshpai, Janis Ivanovs (fourth symphony "Atlantis", 1941), Ovchinnikov and Myaskovsky. Rachmaninov's "Elegie", Op. 3 No. 1 is in E-flat minor, as is his Études-Tableaux Op. 39 #5. These pieces are noted for being dark and mysterious, a mood this key has. This mood is shown even in the later jazz music "'Round Midnight" and "Take Five", which are also in the key.
The second movement to Gustav Mahler's Eighth Symphony has a long orchestral and choral introduction in E-flat minor. The dark orchestral introduction to Beethoven's only oratorio, Christ on the Mount of Olives, is also in this key.
F-sharp major
F-sharp major is a major scale based on F-sharp. Its key signature has six sharps.
Its relative minor is D minor, and its enharmonic equivalent is G major.
This key is not used often in orchestral music except to modulate. It is used more often in piano music, like Scriabin's sonatas. When piano music in this key needs to be arranged for orchestra, sometimes it is better to change it to F or G major. If F-sharp major needs to be used, transposing instruments in B flat should have their music written in A-flat major, not G-sharp major.
The Presentation of the Rose scene in Act Two of Richard Strauss's opera Der Rosenkavalier is written in F-sharp major.
F-sharp major is the key of Beethoven's Piano Sonata, Op. 78, of Chopin's Barcarolle, of Liszt's Hungarian Rhapsody No. 2, of Mahler's unfinished Tenth Symphony, Erich Korngold's Symphony Op. 40, and Scriabin's Fourth Sonata.