The main differences between a C melody and an alto saxophone are their size, pitch range, and historical context.
C melody saxophones were developed in the early 20th century as a transitional instrument between the traditional orchestral instruments and the emerging jazz band instruments. They have a smaller bore than alto saxophones, producing a brighter and more focused sound. C melody saxophones are pitched in the key of C, which means that when a C melody saxophone player reads a C on the sheet music, the note produced is a concert pitch C. In contrast, alto saxophones are pitched in the key of E-flat, which means that when an alto saxophone player reads a C on the sheet music, the note produced is a concert pitch E-flat.
Alto saxophones are smaller than C melody saxophones, making them easier to hold and play. They have a warm and expressive tone and are a popular choice for jazz, rock, and pop music. The alto saxophone has a wider range than the C melody saxophone and is capable of producing higher notes.
The C melody saxophone was popular in the 1910s and 1920s but fell out of favor due to its limited use in ensemble playing and the emergence of more specialized saxophones such as the alto, tenor, and soprano. Today, C melody saxophones are considered rare and collectors' items, while the alto saxophone remains a popular instrument in many genres of music.