30. Selection of track

Figure 30.1 Click on thumbnail for full size image.

Figure 30.1 shows the track being selected (notice the vertical line in the Edit pane E7). If a Sequence box was added to the Edit Panel now, it would be placed at the location of this line. The track was selected by a mouse click in the Edit Panel E7.

The properties of the track are:

• Description: A free format text field that describes what this track contains, e.g. 'Guitar bass chords'.
• Start time: Start time (in seconds) of the track in the composition
• Duration: Maximum duration (in seconds) of the track in the composition - no computation takes place outside this period (ie before start time or after start time + duration).
• Left channel ext./mult.: If a left channel graph has been specified, this indicates the range of y-values to which the left channel graph is scaled. For example, if a value of 3 is specified, then the maximum y-value that will be returned is 3. If a left channel graph has not been specified, this indicates a multiplier which is applied uniformly to the left channel. Use smaller values of this parameter to make the sound of this track quieter on the left channel/speaker, larger values to make it louder.
• Left channel graph: Use this graph to effect a change to how loud or quiet this track is on the left channel/speaker over time. Higher graph y-values will make it louder, small y-values will make it quieter.
• Left channel graph invert-X: Inverts the y-values of the left channel graph relative to the x-axis. For example, with a left channel ext. of 1, a y-value of 0 would return 1, 0.25 -> 0.75, 0.5 -> 0.5, 0.75 -> 0.25, 1 -> 0. If the same graph is used for the left and right channels, but only one has the invert-X set, then at any moment, the track values on one channel will be the exact inverse of the other. This can be used to create the effect of a sound 'moving' from the left speaker to the right one, or vice versa.
• Left channel graph invert-Y: Inverts the x-values of the left channel graph relative to the y-axis. For example, with a left channel ext. of 1, a graph that starts at 1, and decays to 0, would, when inverted about the y-axis, start at 0, and then sharply rise to 1 at the end.
• Right channel ext./mult.: If a right channel graph has been specified, this indicates the range of y-values to which the right channel graph is scaled. For example, if a value of 3 is specified, then the maximum y-value that will be returned is 3. If a right channel graph has not been specified, this indicates a multiplier which is applied uniformly to the right channel. Use smaller values of this parameter to make the sound of this track quieter on the right channel/speaker, larger values to make it louder.
• Right channel graph: Use this graph to effect a change to how loud or quiet this track is on the right channel/speaker over time. Higher graph y-values will make it louder, small y-values will make it quieter.
• Right channel graph invert-X: Inverts the y-values of the right channel graph relative to the x-axis. For example, with a right channel ext. of 1, a y-value of 0 would return 1, 0.25 -> 0.75, 0.5 -> 0.5, 0.75 -> 0.25, 1 -> 0. If the same graph is used for the left and right channels, but only one has the invert-X set, then at any moment, the track values on one channel will be the exact inverse of the other. This can be used to create the effect of a sound 'moving' from the left speaker to the right one, or vice versa.
• Right channel graph invert-Y: Inverts the x-values of the right channel graph relative to the y-axis. For example, with a right channel ext. of 1, a graph that starts at 1, and decays to 0, would, when inverted about the y-axis, start at 0, and then sharply rise to 1 at the end.
• Keep left inter. file: Indicates whether an intermediate file for the left channel should be kept. It is necessary to set this flag if you want the left channel to be included in track 0 (ie the overall composition), or if you are having memory problems (using the intermediate file is more efficient with internal memory, although Compute Stereo will be a little slower).
• Keep right inter. file: Indicates whether an intermediate file for the right channel should be kept. It is necessary to set this flag if you want the right channel to be included in track 0 (ie the overall composition), or if you are having memory problems (using the intermediate file is more efficient with internal memory, although Compute Stereo will be a little slower).
• Keep intermediate file: Indicates whether an intermediate file for this track should be kept. It is necessary to set this flag if you want to compute stereo for this track, and consequently include it in track 0 (ie the overall composition). The advantage of un-setting it is it saves a little disk space and computation time if you don't intend to compute stereo, or include this track in the final composition. A bug in version 2.2 (and possibly 2.1) means it is not possible to un-set this flag.
• Include in track 0: Indicates whether this track should be included in track 0 (ie the overall composition). Technically, it is whether the left or right intermediate files (or both) should be included in the composition, which means that one or both must have been computed (ie Compute Stereo must have been invoked with the 'keep left inter. file' and/or the 'keep right inter. file' flags set), and the corresponding 'keep left inter. file'/ 'keep right inter. file' flags should still be set when the (menu) function Track0 -> Compute is invoked.

The 'Compute kwik' button, behaves the same as the 'Compute' button, except if there are intermediate files that have been computed for the descendants of the track (Sequence boxes, Chord Groups etc.). If an intermediate file is found for a given Sequence box, this gets used, and no detailed computation for that Sequence box and its descendants takes place. This has the advantage of speed, but could result in an unexpected result if any property values of the Sequence box or its descendants have been altered, but without the Sequence box intermediate file having being re-computed. If the Sequence box does NOT have an intermediate file, then the 'Compute kwik' function will look for any intermediate files used by the descendants of the Sequence box (Chord group, Repetition Group, Sound box etc.); intermediate files at lower nesting levels take priority over intermediate files at higher nesting levels, e.g. an intermediate file associated with a chord group would be used if found, ignoring any intermediate files associated with descendants of the chord group, such as harmonic boxes.

Notice also that the toolbar has been dragged into the vertical position, rather than the horizontal position shown in previous pages of this tutorial. It is a good idea to have the toolbar in this (ie vertical) position if you are having problems moving the vertical divider that splits the main screen - this is because of the horizontal toolbar getting in the way, as it cannot be shrunk beyond a certain point.