Click the buttons to navigate through screens and create/play music. To delete your entire track, hold down both R and D keys at the same time, and the entire track will be deleted. If the Metronome variable is 0 or less, it'll be off. If it is 0.01 or higher, it will be on. You probably will notice this, but the further right it is from 0.01, the slower it gets. (there are two hidden key combinations.. try and find them without looking inside for them)
If you are noticing longer waits then what the rests are set to, then try going to Turbo Mode. To activate Turbo Mode, shift left click the green flag. This will toggle it Turbo Mode on and off. Unlike most of the projects I've made, this one has a savecode feature, allowing you to share your tracks! :)