GTT is an online tool to test your GRUB_INIT_TUNE beforehand.
Just enter a GRUB_INIT_TUNE using the following format:
tempo freq duration [freq duration freq duration...]
Where:
tempois the base time for all note durations, as beats per minute. 60 means 1 second notes. 120 means 0.5s notes, etc.freqis the first part of a note. Indicates its frequency in hertz. 262 is a Middle C. 0 means silence.durationis the second part of a note. Indicates its duration measured in bars. With a tempo of 60, 1 means a one second note, 2 means a two seconds note.
Check this gist for ideas & cool tunes. Thanks to @jtagcat for the suggestion.
You can contribute using the guidelines described here. Thank you in advance for your contributions.
You can help by reporting bugs, suggesting functionalities or contributing with new tunes over here.