Abstract: Each of seven modified trumpet tubes is connected by a series of tubular "Y" connections to a single, conventional mouthpiece. Each modified tube is similar to a conventional trumpet except that its three manually-operated finger valves and associated valve slides have been replaced by a single, generally U-shaped tubular slide, which is slidably mounted on the outer end of the usual loop which is formed in the trumpet tubing. The slides are of slightly different lengths, and each is adjusted so that the overall effective axial length of each trumpet tube (from the mouthpiece to its bell) is equal to one of the seven different tube lengths, which are required to produce the seven different semitones capable of being produced by a conventinal trumpet. The entire chromatic trumpet range can be played simply by applying proper lip vibrations to the mouthpiece.