Paul E. Dworak, University of North Texas

By using ear training drills, freshman college music theory students develop the ability to notate the pitch and duration of the tones that constitute intervals, rhythms, melodies, chords, and progressions of harmonies. They also learn to name relationships among sounds in a way that identifies the contexts that these sounds define.

An ideal ear training drill environment should enable a student to write melodies and harmonies by using standard musical notation. It should also provide the student with instant feedback on errors in a solution, and it should allow the student to hear an incorrect solution and to compare it with the correct answer so that the student can refine his or her listening process.

The graphical user interface makes it possible to notate musical sounds by using musical notation. The mouse acts as a pen and the screen acts as a piece of paper onto which staves, notes, accidentals, rests, ties, and chord symbols can be drawn by the student. The courseware described in this paper was developed for the Macintosh family of computers because this family of hardware not only has the required graphics capabilities, but also can play sound using internal sound sources or external MIDI keyboards. In addition, the support for graphics and sound is fairly consistent over the complete line of Macintosh products, making it possible to deliver one product to users with different vintages of equipment.

This presentation focuses on the graphical user interface objects that students use to create musical scores that represent their solutions to ear training exercises. Student responses are represented by palette choices that can be selected with the mouse. Palettes are windows designed to hold icons that symbolize the various actions a person can perform while using the software. A palette can be designed to represent only the meaningful responses that a student can make in any type of exercise. Actions that are inappropriate to the type of exercise, for example, drawing accidentals in a rhythmic dictation, can readily be disallowed. Courseware developed using object oriented techniques is intuitive and easy to use because it is built from functional units that correspond with activities actually carried out by students who complete an ear training exercise.

The courseware discussed in this presentation accompanies the freshman ear training text Basic Ear Training Skills, written by Robert Ottman and this author. This text includes drills in interval recognition, rhythmic dictation, melodic dictation, chord recognition, and harmonic dictation. These five topics are distributed among twenty-five chapters and are supported by approximately 2,000 exercises. The accompanying courseware was written in C++ using MacApp, an object oriented development system for Macintosh applications created by Apple Computer Corporation.

The text was designed specifically to be used in conjunction with the computer and contains two types of drills: Part A exercises introduce students to a listening problem and are intended to be completed in class. The instructor uses the piano as a sound source, and students write solutions to each exercise in their book or on a piece of paper. At the direction of their instructor, they can also check their answers by referring to the solutions given in the back of the book. The Part A exercises can also be completed in the computer lab, using the computer's internal sound generator or a MIDI keyboard as a sound source. The computer displays the correct answer when directed by the student.

In Part A drills, the student only performs three actions: play the question, see the answer, and continue with the next example. To play the question, the student clicks a control that looks like the play button on a compact disc player. To see the answer, the student clicks a button labeled "See." To proceed to the next question or to review the previous question, the student clicks the appropriate arrows (see Figure 1).

Fig. 1. Controls for listening to questions and seeing answers.

Part B exercises, which form an interactive drill and practice environment, give the student additional practice in the listening problem being studied and are contained exclusively in the accompanying courseware. The student can hear an example, enter a solution, check the solution, change an incorrect solution, and see the correct answer.

After using the "play" control to hear the question, the student records a solution by using the mouse. In multiple choice exercises, the student clicks the mouse on visual representations of the possible answers to record a solution. In dictation exercises, which are the focus of this paper, the student uses the mouse to select from a palette of possibilities a note’s pitch and rhythmic value, its accidental, if any, the Roman numeral and figured bass of chords, and nonharmonic tone designations, where required.

After entering a solution, the student asks that it be checked. If it is incorrect, the student can compare the solution with the correct answer both visually and aurally. The student also can correct a solution that includes errors or can continue with another question. In Part B exercises, many of the examples are randomly selected, which enables students to receive as much practice as they wish.

A palette is a floating window that contains icons. A floating window is one that can be moved freely around the desktop and that always remains visible above all other views. The palette shown in Figure 2 contains all the icons that a student might see in an ear training exercise.

Fig. 2. A palette of tools for completing ear training exercises.

A student selects a tool from the palette by clicking on it with the mouse. The cursor then assumes the shape of the selected tool, and this shape represents the action that the student wishes to perform. A cursor shaped like a note head enables the student to add a note to a score. A figured bass cursor enables the student to indicate the inversion of a chord, and so forth.

The leftmost icon represents a selection tool that has several uses. It selects the beat where the next note added to the score will appear. This enables a student to enter notes of a solution in any order. It also selects existing beats for change or for deletion. Finally, it selects noteheads already on the staff—these can be dragged to a different line or space to change the note’s pitch.

The next icon represents the beat selection tool. This enables a student to add a note to a score and to specify its rhythmic value and its pitch. When this icon is clicked, a popup palette appears. It contains all the rhythmic values that a student might choose (see Figure 3).

Fig. 3. Selection palette for all possible rhythmic values.

Clicking on one of the rhythmic values changes the icon that appears in the main palette, which represents the current choice. Note that some of the rhythmic values are dimmed. These cannot be selected by the student. Students are not permitted to select a rhythmic value greater than the duration remaining in the measure, and they cannot select values less than the smallest metric division or subdivision that is studied in an exercise. These restrictions not only simplify error checking, but they also focus the student’s attention on one of the main issues of an exercise—completing a solution that reflects an understanding of how rhythmic values can be placed within a meter. The student can select notes, rests, accidentals, ties, nonharmonic tones, Roman numerals, and figured bass symbols in a similar way.

All these choices need not be made in every type of exercise. A rhythmic dictation exercise only needs rhythmic values and ties. A melodic dictation exercise also requires accidentals. Roman numerals, figured bass symbols, and nonharmonic tone names will be used only in harmonic dictation exercises. Various types of exercises can be defined by specifying the tools that will constitute the exercise’s palettes. In this courseware, a resource containing this information is associated with each exercise. Figure 4 shows examples of exercise definition constants that are used to specify the palette tools employed in some of the easiest rhythmic, melodic, and harmonic dictation exercises.

Fig. 4. Defining the tools that constitute palettes.

Each of these exercises identified in this figure has a finite number of questions, for example, the exercises presented are not randomly generated. Each uses a ScorView object for displaying and playing the correct answer as well as a ScorWriteView object, which is a simple score editor. The rhythmic dictation exercise also uses note and rest tools, but no ties. The melodic dictation exercise adds accidental and tie tools to the palette. The harmonic dictation exercise does not use accidentals and ties, but it does use Roman numerals. Since all its chords are in root position, it does not use figured bass symbols.

Each of the constants shown in Figure 4, for example "exUsesRhythmTools," is simply a number that represents an object. Each type of exercise is also represented by a constant, for example "PartBHarmonicID." This value is simply the numerical sum of all the constants that represent the objects used in that type of exercise. Various kinds of exercises can be specified by identifying the objects that constitute the exercise environment.

In this way, the palette appropriate for any exercise can be assembled when the student selects that exercise. Since the palette and its icons are objects that know how to accept selections and alter the cursor, any icons placed in the palette will have this capability without any additional coding. The tools associated with each icon are also assembled for the lesson that has been selected. Each exercise has a tool resource that identifies the icons that will be drawn in the popup palette when the student selects a particular type of tool.

Limiting the choices available in the popup palette enables the student to select only from possible choices. In a simple harmonic dictation exercise, the student sees only I and V because the exercise uses only tonic and dominant chords. Exercises that use secondary dominant chords display these possibilities as well.

Figure 5 shows a partially completed rhythmic dictation exercise.

Fig. 5. Completing a rhythmic dictation exercise.

Note the bracket in measure 2. This is the insertion point. To add a note on this beat, the cursor (which in this figure is the note immediately beneath the bracket) must be positioned within this space before the mouse is clicked. Clicking the mouse in measure three would move the insertion point to that measure and would add a note on the first beat of the measure. Clicking in measure one would not add a note, since that measure is already complete. Notice that the only note value that is not dimmed is the quarter note. This is the only duration that can be used to complete measure two. The "Check" button remains dimmed until the student completes the solution.

Figure 6 shows a completed melodic dictation exercise that has already been checked and that has one error. To enter the solution, the student selects a rhythmic value from the popup palette and positions the note cursor on the desired line or space. Clicking the mouse inserts a beat with the specified pitch at that location. This solution contains a pitch and rhythm error. The position of the errors is indicated. The student is invited to try again. Once the solution has been checked, the student can play both the solution and the correct answer to hear what the marked errors sound like. To correct the error, the student positions the insertion point over the incorrect rhythm, deletes it (with the Backspace or Del keys) and inserts the correct duration on the appropriate line or space.

Figure 7 shows a harmonic dictation exercise in which the Roman numerals have already been identified. The first bass note is ready to be added to the solution. Notice that only the popup palette for Roman numerals is visible, and that it contains only I and V. The student controls which popup palettes remain on the screen and can position them anywhere on the desktop.

The graphical user interface provides the student with a very intuitive environment for completing an ear training drill. Object-oriented techniques enhance this environment in two ways: they provide the student with flexibility and control in completing any drill, and they enable a very large curriculum to be integrated into a single, consistent user interface. As a result, the student can navigate easily through a large number of diverse types of drills, all contained within one application.