Try ii-Music for Free
"No need to read music or memorize scales to give this a go-- all you need is a love of music" (from the Skoog Music website)
ii-Music operates using cursor position and "dwell to click"- so it's usable with most cursor control systems such as head trackers. Dr. Benjamin Schogler promoted the free version to the QIAT list this week, noting "We are keen to get feedback and put the software put through its paces. ... It can be used for music performance and production, or to support sensory play and developing use of eye gaze."
The free version is feature limited but not time limited.
Learn more at this Skoog Music web page
Reminder: MassMATCH makes no endorsement, representation, or warranty expressed or implied for any product, device, or information set forth in this email or on its Web site. MassMATCH has not examined, reviewed, or tested any product or device here referred to.