the King Saxello soprano, the C.G. Conn mezzo-soprano saxophone keyed in F, and the Conn-O-Sax saxophone – English horn hybrid. French saxophonist and educator Jean-Marie Londeix greatly expanded the saxophone repertoire and available techniques in the second half of the 20th century, commissioning a great deal of new saxophone works with extended techniques, including those by Denisov, Lauba, Rossé, and Rolin. Modern saxophone emerges The modern layout of the saxophone emerged during the 1930s and 1940s, first with right-side bell keys introduced by C. G. Conn on baritones, then by King on altos and tenors. The mechanics of the left hand table were revolutionized by Selmer with their Balanced Action instruments in 1936, capitalizing on the right-side bell key layout. In 1948 Selmer introduced their Super Action saxophones with offset left and right hand stack keys. Thirty to forty years later this final Selmer layout was nearly universal on all saxophone models. The high F key was also first introduced as an option on the Balanced Action model, although it took several decades for it to gain acceptance because of perceived deleterious effects on intonation in its early implementations. Marcel Mule established study of the saxophone as a classical instrument at the Conservatoire de Paris from the 1940s. Larry Teal did the same in the United States at the University of Michigan a decade later. A number of other American institutions have since become recognized homes for the study of classical saxophone. They include Northwestern University, Indiana University, and the Eastman School of Music. Usage In military bands The saxophone first gained popularity in military bands. Although the instrument was initially ignored in Germany, French and Belgian military bands were quick to include it in their ensembles. Most French and Belgian military bands incorporate at least a quartet of saxophones, comprising an E baritone, B tenor, E alto and B soprano. These four instruments have proven the most popular of all Sax's creations with the E contrabass and B bass usually considered impractically large and E sopranino insufficiently powerful. British military bands tend to include at minimum two saxophonists on alto and tenor. In classical music The saxophone was introduced into the concert band, which usually calls for an E alto saxophone, a B tenor saxophone, and an E baritone saxophone. A concert band may include two altos, one tenor, and one baritone. A B soprano saxophone is also sometimes