The program HearTri was written in Microsoft Basic in 1987 at the request of Ross Bauer. It was compiled in Microsoft Quick Basic in 1988. This program carries no warranties, expressed or implied. HearTri is freeware from David Rakowski, 51 Big Tree Way, Woodside, CA 94062.
The intent of the program is to drill the user on three-note sonorities chosen randomly. In contemporary music theory, three note groups are called trichords. There are 12 unique trichord TYPES. Trichords are named by giving the distance in semitones up or down from a starting pitch, called 0 (zero). Hence a 012 trichord consists of the starting note, the note one semitone higher (or lower) and the note two semitones higher (or lower). The notes F, F#, A form a 014 trichord, counted UP with F as zero. The notes G, B, C form a 015 trichord, counted DOWN from C as zero. The trichord naming conventions come from the most closed registral position possible for the three-note group.
The following is a list of the 12 trichord types in order of "closeness" with two examples of each:
012 C,C#,D C,B,B-flat
013 C,C#,D# C,B,A
014 C,C#,E C,B,G#
015 C,C#,F C,B,G
016 C,C#,F# C,B,F#
024 C,D,E C,B-flat,A-flat
025 C,D,F C,B-flat,G
026 C,D,F# C,B-flat,G-flat
027 C,D,G C,B-flat,F
036 C,E-flat,G-flat C,A,F# (also known as a diminished triad)
037 C,E,G C,A-flat,F (either a major or minor triad)
048 C,E,G# C,G#,E (augmented triad)
A trichord type refers to both a three-note pitch group and its inversion: hence the major and minor triads are both the same trichord type since they are inversions of each other.
Using HearTri is quite simple. Two buttons prompt you to Play a Trichord (or to play it again) or to quit the program. Two Check boxes give you the option of hearing the trichord arpeggiated or as a block chord. And twelve buttons, each with one trichord type, are for your guess of the trichord played. A window at the right tracks your progress. You are told if your choice is right or wrong, and if wrong the trichord is sounded again. When you quit, you are given your statistics broken down in terms of how many guesses you got right and wrong for each trichord type.
There are known bugs in the program, none of them serious. The progress window does NOT refresh after a window has been moved in front of it ╤ only the progress numbers refresh regularly. You must set the volume level of your Mac from the Control Panel ╤ the program has no volume option. Sometimes the program hangs when used in MultiFinder. Finally, due to Microsoft's strange random function, the first trichord it plays is ALWAYS 015.
Questions about technical aspects of trichord types may be answered in Allen Forte's book "The Structure of Atonal Music." Questions or suggestions for refinements may be directed to me at the above address. This program is free and may distributed in any manner, shape or form whatsoever. Contributions from those so inclined may be sent voluntarily to the Music Department, Stanford University, Stanford CA 94305. The author is (1988-89) a lecturer in Music Theory at Stanford.
