Some things can be selected (left click) and some things have context menu (right click). Scroll down for more stuff.
Instruments
Patterns

Record pitches from audio
This is a easy way to choose notes because you can use voice. You need to select instrument before starting
Last note:
Add octaves (12 notes): Recording BPM:
Load JSON:

This uses pitch.js (https://github.com/audiocogs/pitch.js) which uses fft.js (https://github.com/auroranockert/fft.js)