Start and Stop Times

See also Swing.

Start Times and Stop Times, which you can edit directly with the MIDI Tool, essentially refer to the attack and release of a note. They don’t refer to the notated durations of the notes; instead, they relate those notated values to the captured MIDI data. Captured MIDI data is the MIDI information generated by your original performance in HyperScribe, before it’s quantized and transcribed into notation.

The terms Start Time and Stop Time refer specifically to the difference between the quantized duration of a note (that is, its starting and ending points when given its full notated value) and your actual attack and release of the note in your performance. In the figure below, the indicated Start Time is a positive number (because the note was played slightly after the beat), and the Stop Time is a negative number (because the note was released slightly before the next beat):

The Start Time is the difference between the actual (performed) attack point and the notated, quantized attack point. The Stop Time is the difference between the actual (performed) release point and the notated, quantized release point. These differences can be either positive or negative; Stop Time (a), above, is a negative number—because the note was released early—but Stop Time (b) is positive.

Start and Stop Times are measured in very small rhythmic increments called EDUs (ENIGMA Durational Units), of which there are 1024 per quarter note. (A full table of EDU equivalents appears in the Equivalents section of the Appendix, see Equivalents.) If you hold down each note you play for precisely its notated value, with 1024th-beat accuracy, the Start and Stop Times will both be zero, with no difference between the quantized and the actual attack point of the note. Of course, no human can play that precisely.

For a more complete discussion of Start and Stop Times and the MIDI Tool, see Chapter 6: Playback in the Installations & Tutorials.

To edit the start and stop times of selected notes

1. From the Window Menu, choose Advanced Tools. Click the MIDI Tool  , and select the region whose playback data you want to edit. Click to select one measure, shift-click to select additional measures, drag-enclose to select several on-screen measures, click to the left of the staff to select the entire staff, or choose Select All from the Edit Menu.
2. If the region you wish to edit is on one staff, double-click the highlighted area to enter the MIDI Tool split-window. Select the specific notes whose Start and Stop Times you want to edit. Once you’re in the MIDI Tool split-window, you can select entire regions of notes by dragging through the “graph” area of the window. You can also select specific notes to edit by selecting their handles (in the notation display at the bottom of the window). Select one handle by clicking, additional handles by shift-clicking, a group of handles by drag-enclosing, and additional groups by shift–drag-enclosing.
3. From the MIDI Tool Menu, choose Note Durations. If you’re in the MIDI Tool window, you can click the Note Durations icon (second from the top) instead. Once you’ve selected the notes to be affected, you can apply one of the MIDI Tool’s Menu commands:
4. Choose the desired command from the MIDI Tool Menu. Each command brings up a dialog box in which you can specify how the selected notes are to be altered. Set To allows you to give every note in the selected region the same Start or Stop Time. In this way, you can shorten or delay all notes by the same amount. Scale gradually shortens (or lengthens) the Start or Stop Times of the selected notes from one value to another. Add alters every selected note’s Start or Stop Time by a positive or negative value you specify. Percent Alter increases or decreases the selected notes’ durations by a percentage of their current values—ideal for creating a staccato effect for the selected music. Limit lets you set a maximum and minimum Start Time and Stop Time value for the selected notes, in effect pulling the beginning and ending of each note closer to the beat. You can think of the Limit command as a form of quantizing.

The Alter Feel command changes the Start and Stop Times of Downbeats, Other Beats, and Backbeats. (Backbeats are defined as the half beats [in a duple meter] or the second and third offbeats [in a triple meter]. For some interesting uses of the Alter Feel command, see Swing.) Finally, Randomize alters the selected notes’ durations by a random amount, giving the music a less quantized, more human feeling. You might enter an EDU value of 1/16 (or less) of the predominant rhythmic values in the music; to subtly soften the rhythmic precision of an eighth note (512 EDUs) passage, for example, you might type 32 into the Start and Stop Times boxes.

5. Enter the desired degree of Start or Stop Time modification, and click OK.
6. Close the MIDI Tool split-window by clicking the MIDI Tool.

To erase Start and Stop Time editing done with the MIDI Tool

1. From the Window Menu, choose Advanced Tools. Click the MIDI Tool  . The MIDI Tool Menu appears. Make sure Note Durations is still selected in the menu.
2. Select the region in which you edited Start and Stop Times, and press BackSpace. Or, use the Selection Tool to clear Continuous Data.

To copy Start and Stop Time editing done with the MIDI Tool

1. From the Window Menu, choose Advanced Tools. Click the MIDI Tool  . The MIDI Tool Menu appears. Make sure Note Durations is selected in the menu.
2. Select the region in which you edited Start and Stop Times.
3. Drag the first source measure so that it’s superimposed on the first target measure. If the first target measure is not on-screen, scroll until you see it. Then, while pressing ctrl and shift simultaneously, click the first target measure.

In either case, the Copy MIDI Data dialog box appears. (This dialog box does not appear if you copy to the same measure in a different staff).

4. Type the number of times you want to copy the material (horizontally). Click OK. The Start and Stop times are copied onto the notes which fall on the same rhythmic location as source notes.

To create a legato playback

1. From the Window Menu, choose Advanced Tools. Click the MIDI Tool  . The MIDI Tool Menu appears.
2. Select the region you want to sound more legato. See Selecting music for more information.
3. From the MIDI Tool Menu, choose Note Durations.  
4. From the MIDI Tool Menu, choose Percent Alter. The Percent Alter dialog box appears.
5. Enter 105 for Stop Times and click OK.