SWAM version 1.0 had bugs. Version 3.8 (current) has:
Audio interfaces process sound in chunks called buffers. If your computer cannot finish calculating the complex physics of the SWAM saxophone before the next buffer is due, it produces a crack or pop. swam saxophones work crack link
: As the player covers and uncovers the tone holes by pressing the keys, the length of the vibrating air column changes. This alteration in length changes the pitch of the sound produced. SWAM version 1