detachable neck because the neck receiver/tenon system is prone to excessive wear and can develop leaks over time which hinder the instrument's playability if not corrected, so due to some players' preference for curved necks, occasionally one-piece instruments are bent during manufacturing above the octave key (e.g. the Yamaha YSS-62R and YSS-82ZR). Some manufacturers also produce fully curved sopranos which look much like a small alto saxophone with a straighter neck/crook, as well as 'tipped-bell' sopranos which are straight but have the bell angled upward somewhat and are typically used with a curved neck (these are often called 'saxellos' for their resemblance to the somewhat rare Saxello model produced by King in the 1920s, though an actual Saxello's bell is angled more and its bore is different). All variants have the same keys and range as the traditional straight soprano, but as with the necks, some players believe curved and tipped-bell sopranos sound warmer and less nasal. Due to the higher pitch of the soprano, it is more sensitive with respect to intonation than the lower saxophones, so a player must have more skill with breath support, tongue and soft palate position, and embouchure (collectively known as voicing). It is also less forgiving of poor maintenance than lower saxophones. This has led to the common belief that soprano is either inherently out of tune, or far more difficult to play than lower saxophones, but many experienced players and teachers disagree with these sentiments. Soprano saxophone mouthpieces are available in various designs, allowing players to tailor their tone as desired. In classical music The soprano saxophone is mainly used as a solo and chamber instrument in classical music, though it is occasionally used in a concert band or orchestra. It is included in the saxophone quartet and plays a lead role. Many solo pieces have been written for it by composers such as Heitor Villa-Lobos, Alan Hovhaness, Jennifer Higdon, Takashi Yoshimatsu, Charles Koechlin, John Mackey, Miklos Maros, Marc Mellits, and Belinda Reynolds. As an orchestral instrument, it has been used in several compositions. It was used by Richard Strauss in his Sinfonia Domestica, where included in the music are parts for four saxophones, including a soprano saxophone in C. It is also used in Maurice Ravel's "Boléro" and has a featured solo directly following the tenor saxophone's solo. Vincent d'Indy includes a soprano in his opera Fervaal. Notable classical soprano saxophonists