Use the slider in the top bar to select which instrument you are editing. Once you are finished selecting which beats you would like to be played, select "Add Measure" to add it to your scene. Every instruments has it's own set of measures. When you click "Add Measure", you are only adding a measure for the instrument you have selected. For Example: If you add 1 measure to the High Hat and add 2 measures to the Tom Drum, the High Hat measure will repeat itself while the Tom Drum will play both measures before repeating. When selecting beats for the vibra cannons, a piano keyboard will pop up allowing you to pick the note you'd like for that beat. Only 16th note subdivisions and simple sounds for now, others to come later. Enjoy playing musical instrument simulation here at Y8.com!