A transposing instrument pitched in the key of B♭, modern soprano saxophones with a high F♯ key have a range from B♭3 to F♯6 and are therefore pitched one octave above the tenor saxophone. Some saxophones have additional keys, allowing them to play an additional F♯ and G at the top of the range. These extra keys are commonly found on more modern saxophones. Additionally, skilled players can make use of the altissimo register, which allows them to play even higher. There is also a soprano pitched in C, which is less common and until recently had not been made since around 1940.
The soprano saxophone can be compared to the B♭ clarinet, although the clarinet can play an augmented fourth lower and over a fifth higher. Due to the smaller bore of the soprano, it is less forgiving with respect to intonation, though an experienced player will use alternate fingerings or vary breath support, tongue position or embouchure to compensate. Professional players will use the technique of voicing to fix problems with intonation. Due to its similarity in tone to the oboe, the soprano saxophone is sometimes used as a substitute for it.
In addition to straight sopranos, there are also slightly and fully curved sopranos. The fully curved variety looks much like a small alto saxophone with a straighter crook. There is some debate over the effect of the straight and curved neck, with some players believing that a curved neck on a soprano gives it a warmer, less nasal tone. The soprano has all the keys of other saxophone models (with the exception of the extra 'A' on some baritones and altos) and some (e.g. those made by Yanagisawa, Selmer, and Yamaha) may have a top 'G' key next to the F♯ key.
Soprano saxophone mouthpieces are available in various designs, allowing players to tailor their tone as required.
In 2001, François Louis created the aulochrome, a woodwind instrument made of two joined soprano saxophones, which can be played either in unison or in harmony.