The saxophone was developed in 1846 by Adolphe Sax, a Belgian-born instrument maker, flautist, and clarinetist working in Paris. While still working at his father's instrument shop in Brussels, Sax began developing an instrument with the projection of a brass instrument and the agility of a woodwind. He wanted it to overblow at the octave, unlike the clarinet, which rises in pitch by a twelfth when overblown. An instrument that overblew at the octave would have identical fingering for both registers. Prior to his work on the saxophone, Sax had made several improvements to the bass clarinet by improving its keywork and acoustics and extending its lower range. Sax was also a maker of the then-popular ophicleide, a large conical brass instrument in the bass register with keys similar to a woodwind instrument. His experience with these two instruments allowed him to develop the skills and technologies needed to make the first saxophones. Adolphe Sax created an instrument with a single reed mouthpiece like a clarinet, conical brass body like an ophicleide, and the acoustic properties of both the French horn and the clarinet. Having constructed saxophones in several sizes in the early 1840s, Sax applied for, and received, a 15-year patent for the instrument on June 28, 1846. The patent encompassed 14 versions of the fundamental design, split into two categories of seven instruments each and ranging from sopranino to contrabass. Although the instruments transposed at either F or C have been considered "orchestral", there is no evidence that Sax intended this. As only 3 percent of Sax's surviving production were pitched in F and C, and as contemporary composers used the E♭ alto and B♭ bass saxophone freely in orchestral music, it is almost certain that Sax experimented to find the most suitable keys for these instruments, settling upon instruments alternating between E♭ and B♭ rather than those pitched in F or C, for reasons of tone and economy (the saxophones were the most expensive wind instruments of their day). The C soprano saxophone was the only instrument to sound at concert pitch. All the instruments were given an initial written range from the B below the treble staff to the F, one space above the three ledger lines above staff, giving each saxophone a range of two and a half octaves. Sax's patent expired in 1866; thereafter numerous saxophonists and instrument manufacturers implemented their own improvements to the design and keywork. The first substantial modification was by a French manufacturer who extended the bell slightly and added an extra key to extend the range downwards by one semitone to B♭. It is suspected that Sax himself may have attempted this modification. This extension is now commonplace in almost all modern designs, along with other minor changes such as added keys for alternate fingerings. Have a nice day.