An arpeggiator is a feature in many analog synthesizers that cycles through all of the notes in a chord in a specified order. This is a great tool to create interesting sounds and patterns; unfortunately, bandlab does not have an arpeggiator built into their synthesizers.
This is a simplified arpeggiator that lets you pick between a few patterns, major and minor chords, and two different sounds. As an introduction to how arpeggiators work it’s great, however, it does lack some more robust features that would make it a good tool for composing.
This arpeggiator is a little more complicated, but it allows for many different types of chords, modes, arpeggio patterns, keys, arpeggio steps (the number of notes in each pattern), and tempo!
Try out a few different chord progressions and have fun experimenting with the results!