Overview

Not surprisingly, the Bars track displays the locations of every measure in a song. It is also used to define loop regions (click-and-drag in the top-half of the track) and to position the playhead (click in the bottom half of the track).

Modifying Bars and BPM

Song Master usually does an excellent job determining beat locations, bar lines, and the time-signature. However, when it doesn't there is usually a quick fix. We'll start with the more common errors and get into more complex scenarios later. 

If the tempo is twice as fast or half as slow 

Sometimes Song Master will say the tempo is two-times as fast as it should be or it may say it is half as slow as it is. We find it pretty easy to tap our foot to the beat of a song. but it's not surprising for beginning and non-musicians to disagree on the rate and will often differ by a factor of 2. Regardless, let's see how to quickly fix this problem. 

Options that control some of Song Master's analysis algorithms are located on the Analyzers tab (see (1) below) on the bottom panel. 

The Analyzer tab displays four separate panels that contain options related to the analyzers. The first panel is for making quick modifications to bar lines and BPM. The Beats panel contains a button for reducing the current bpm in half and another button for doubling it (see (2) in above screenshot). Just click the appropriate button to affect the change as illustrated below:

If bar lines aren't aligned to beat one

To align bar lines with the first beat of a measure, use the  and  buttons on the Beats panel to nudge the bar line one bar to the left or right, respectively:

Finer control of beat placement

If you need finer control over the placement of bar lines you can use the Edit bar times option found on the menu for the Bars track. You can access this menu by right-clicking anywhere on the Bars track or by clicking the little rectangle on the Bars track header column.

 When in bar time editing mode, the bar lines turn orange. You can click and drag a bar line to re-position it. If you need finer control over the placement, you can zoom in. Notice that the mouse cursor changes to two white blocks on either side of the bar line. This is to indicate that any changes you make will change all the bars to the left and to the right.

Sometimes you need to only change the bar lines that are to the right of the mouse. For instance, say a song is in 4/4 time but has a bar with just two beats immediately before the chorus. To correct for this, we need to move all bars starting with the chorus two beats to the left. To move just the bars to the right of the mouse cursor, hold down ctrl+alt (option+command on mac) when clicking the bar line. In the following screenshots, we enter Edit bar times mode, reposition all the bars, zoom in, reposition again with finer control over timing, then we reposition all bars from bar 4 to the end, finally, we exit Edit bar times mode:

When you are finished editing the bar lines, be sure to exit edit mode by unchecking "Edit bar times" in the menu.

 What if the BPM is just completely wrong

If it is not possible to align the bars using the above methods, you can replace Song Master's bars with bars using a fixed BPM. To do this, click the BPM value displayed in the Control bar and type the BPM and hit ↵.  A dialog is displayed to confirm that you want to change ALL bar lines to a fixed bpm. These actions are demonstrated below:

Visually changing the BPM

Similar to Edit bar times, the Edit as fixed BPM mode allows you to adjust bar spacing starting at any bar line. This option is best illustrated in action as shown below. Since we'll be following a typical sequence of actions, we''ll enumerate the steps for your reference.

1. enter Edit bar times mode and position bar 1 to the first down beat
2. enter Edit as fixed BPM mode. If the song you are editing isn't crushed by a limiter you may be able to visually see in the waveform where the beats are and use them to make the necessary adjustments. However, in this example, it'll be easier to adjust it aurally. 
3. create a loop region over several bars and make sure the entire loop is visible (this will allow us to iteratively refine the bar placement, and prevent scrolling).
4. enable the metronome by pressing m. The metronome will give us an aural clue that we will want to have line-up with the beats in our song. Make sure you can clearly hear the metronome. If necessary, you can turn down the volume of the song by using the song's volume on the Tools Panel. 
5. Press space to start playing the loop region. 
6. We want to use bar 1 as our anchor so we click and drag bar 2. As bar 2 is moved, all the bars following it are modified to keep the bpm constant. 
7. If you are visually aligning the beats to waveform peaks then make sure that the playhead marker is positioned at or after bar 1. If it isn't click in the waveform where bar 1 is located to position the playhead to bar 1. This allows you to watch the BPM displayed in the Control bar as you make your adjustments (the BPM displayed is always the BPM at the location of the playhead marker).
8. When we are satisfied with the results, uncheck Edit fixed BPM in the menu.

Add and Delete a Bar

To Add a bar, right-click at the place you want to add the bar and select Add a bar from the pop-up menu. To delete a bar, right-click on the bar you want to delete and select Delete bar from the pop-up menu.

Modifying Bar Placement in a Region

The methods described above allow you to easily change and adjust bar positions for the entire song or from a given point to the end of the song. You can also modify the bars positions in a defined region using the couple of methods described next. 

Create a Loop Region

Create a loop region that encompasses the range of bars that you want to modify. then right-click in the bar track and select Modify bars in loop region... to display a dialog with options on how you want to modify the bars. 

If you know the number of bars in the region, then click use number of bars and enter the number of bars in the edit field to the right. Song Master will calculate the bpm that will fill the loop region with the number of bars requested. 

You can also specify the bpm for the loop region and Song Master will determine the appropriate bar positions using the specified bpm.  It's common to have a bar at the end of the loop region where it wasn't possible to fit a full bar at the requested bpm. In this case you will need to adjust the last bar position (go into Edit bar times mode, press shift; to modify just one bar and drag the bar to the desired time) or delete the last bar.

Drop Note Markers and Convert them to Bar Positions

This method gives you absolute control over each bar position. In this method, with the song playing, drop Note markers (press N key) at the positions you determine for the bars. You can do this for just a section of the song or for the entire song. Once you have added all the markers, select them (ctrl+a or use the mouse to select the first and last markers). Now, right-click in the Notes track and select Convert selected markers to bars.  

Once you've converted the bars, you can delete the markers.

Reset the Bars

You can always go back to the original bars computed by having Song Master re-analyze the song by clicking on the Analyze button in the Analyzers' tab Beats panel.