OnSong expects text-based chord charts to abide by some basic rules. When you import content from third-party sources, some times they use text formatting and special characters in ways that don't work well with OnSong. This can cause chords to not be detected which means they can't be transposed or formatted.
OnSong is pretty flexible with the format of the song, but chords are expected to either be placed above the line of lyrics using spaces to place the chords along with the associated lyrics, or to use square brackets to place the chords on the same line as the lyrics. You can learn more about this and see a visual representation of this in the OnSong user manual.
Here are some common pitfalls that can cause chords to not work correctly.
Rogue square brackets
Some third-party content providers make chord charts available using Chords Over Lyrics, but use square brackets in ways that are not compatible with OnSong. For instance, they may wrap section labels in square brackets. This can cause the section label to appear as a chord, and for chords to go undetected. This causes them to be misaligned, unformatted, and non-transposable.
To fix this, open the Song Editor by tapping the Attachments Menu icon in the Menubar and selecting "Edit Chords and Lyrics", or in OnSong 2020 tap on the text cursor icon to open the Song Editor. You can then manually remove the square brackets from the song content. You can use the Search and Replace feature to speed up this process and replace the square brackets with an empty replace box by tapping on the hammer icon in the Menubar to open the Text Tools Menu. Once you are finished, tap Done. Your chords should now be detected, properly placed, formatted, and transposable.
Missing Chord Formats
Another common issue is if you use bracketed chords, but also place those chords above the text. This will cause the chords to be detected because they are wrapped in square brackets, but they will not be aligned with the lyrics underneath. You may find that they are pushed to the left. This is because the space characters that separate the chords are much narrower than other characters in the font you are using.
To fix this, again, just open the Song Editor by tapping the Attachments Menu icon in the Menubar and selecting "Edit Chords and Lyrics", or in OnSong 2020 tap on the text cursor icon to open the Song Editor. You can then manually remove the square brackets from the song content. You can use the Search and Replace feature to speed up this process and replace the square brackets with an empty replace box by tapping on the hammer icon in the Menubar to open the Text Tools Menu. Once you are finished, tap Done. Your chords should now be detected, properly placed, formatted, and transposable.
Whitespace Characters
OnSong uses spaces to align chords over lyrics. However, some content may use other types of characters such as tab characters to align content. In addition, there are other "gremlins" that can sneak in from time to time and cause alignment issues. While OnSong can use tab characters to some extent, it's best to replace tab characters with spaces. Once again, you can do this by opening the Song Editor and locating any tabs to replace.
You can also use tabs and assign them a certain width. You can adjust this setting by opening the Utilities Menu by tapping on the gear icon in the Menubar and choosing Settings. From there, choose Display Settings > Song Formatting > Spacing for more options.