I recently had a great conversation with the inventor of the Hummingbird music notation, Blake West. I will share some of my thoughts about Hummingbird and how it relates to pitch bracket notation.
Hummingbird uses a traditional five line staff and in large part resembles traditional notation with two primary changes. The note head, which is traditionally used to notate duration, now notates pitch. Each note, A through G, has a distinct note head appearance which helps the musician identify notes on the staff. The other change is the rhythm notation. Hummingbird notes have a horizontal line, a tail, which indicates the relative duration of the notes. Naturally, longer tails are longer notes. Beaming notes together involves a horizontal line above a group of notes.
Hummingbird inherits the advantages of traditional staff notation like polyphony, articulation and ornamentation, and dynamics. The mnemonic for note pitch helps students who are unfamiliar with the staff, but I imagine a variety of different symbols might obscure the melodic and harmonic content of the music. For example, the melody, C E G B, consists of a simple stack of 3rd intervals. In Hummingbird, the four different note symbols do not help the musician recognize the simple melodic pattern of a stack of 3rd intervals. If you shift the same melody up one note, D F A C, you have four new note symbols which look totally different than the first melody. In other words, the Hummingbird note symbols help musicians identify absolute note pitch but not relative pitch, that is, pitch intervals.
In pitch bracket notation, polyphony and rhythm notation are not obvious. I have some solutions in the works which may prove to be an improvement on traditional rhythm notation. But, for now, pitch bracket notation is a notation of melodies. The originality of pitch bracket notation lies its ability to describes complex patterns of pitch intervals which are the building blocks of harmonic and melodic compositions. The emphasis on pitch intervals has proven to be a valuable means of communicating and understanding music. After all, when we listen to music, we care about the intervals between notes, not where those notes sit on the staff.