Post basic sheet music on your Flarum.
composer require zerosonesfun/flarum-ext-chords
composer update zerosonesfun/flarum-ext-chords
php flarum cache:clear
...and you might need to clear your browser cache and cookies too. Are you using cloudflare? Empty that too.
This extension looks for specific bbcode tags and converts them to the code needed so that your sheet music chords are above the lyrics. Wrap the entire song in [song] [/song] and then where you want a chord, use [chord] [/chord]
Example of what you would type into a new post:
[song] These [chord]G[/chord]are lyrics to a [chord]C[/chord] song. [/song]
Change the look of your sheet music by going to assets > extensions > zerosonesfun-chords > styles.css and modify the stylesheet.