You must be in SONG mode, not pattern mode, to use the sequencer. You should have already made your patterns in the beatbox and bassline machines. For the synths, you should already have a preset called up in that machine. If your preset isn't selected in the synths, or your patterns are empty in the beatbox/basslines, you will hear silence if you try to use them in SONG mode. You tap the green box in the upper right to select which instrument/machine to work with.
For the Subsynth and the two PCM Synths, you're looking at a piano roll view where notes go up and down (about 8 octaves, C1 to G#8.). Touch and drag to the right to make notes to write melodies. Note-on info only, no velocity info yet. MIDI version in the works, hopefully with velocity (long-press note, then drag up/down to make a thinner or thicker note?)
For the beatbox and bassline machines, you enter pattern numbers at a specified measure.
PLAY/STOP/Record
PLAY button plays or resumes play. STOP stops. Long-press STOP to go back to the beginning. See Singlecell's video earlier in this post for tips on using the new Record button (version 1.1) Now motion tweaks to EQ, FX level, pan, and volume can all be independently recorded in the Mixer!
Zoom magnifiers (+ and -)
Maximum zoom in is two measures (8 beats). From there, clicking on the zoom out (-) zooms out twice the view: 4 measures, then 8, then 16, 32, up to 64 measures maximum zoom out.
Timeline
Horizontal bar at the bottom of the sequencer page. Every four measures are numbered (1, 5, 9, 13...) Black vertical bar moves when sequencer is playing. Once stopped, this is where play will resume from again. Unless you press somewhere in the timeline while playback is stopped, in which case the orange vertical bar moves to this new start point.
You can press and drag in the timeline to define your loop points. Remember to zoom out if you want to loop a large number of measures.
Pencil tool icon
Select it, then draw (musical notes for the synths) or add pattern number (for beatbox). Draw notes by touching and dragging to the right. Adjust note length by clicking the tail end of the note and moving left or right. Once drawn, notes can also be dragged up/down (pitch) or left/right (time).
When the pencil tool is selected for the beatbox and bassline instruments, which are pattern-based machines, touching a measure opens up a screen which asks you which pattern number you want to put at that measure.
De-select pencil tool, and you can once again drag/scroll thru the timeline to different measures. You can also drag patterns around to different measures when pencil is de-selected.
Three orange bars icon
Multi-select: you can select multiple notes when this icon is enabled. Selected notes turn orange. These notes all become grouped together, and can then be moved or copy/pasted as a group. Great way to make a melody then copy it to use again at different places in the song.
(Note to Singlecell: would be great to copy to a global buffer, so that you can paste those notes onto a different synth track, like say, a PCM piano line gets copied then pasted to be repeated by the Subsynth. Read: for future MIDI use, this could also mean saving a note group as an independent melody that could then be saved/loaded as a musical MIDI pattern. Arps and motifs, anyone? How about custom pre-made drumbeats?)
The X icon
Use it to erase already drawn notes. First, select the note or group of notes, then press X to remove the selected notes. Also can be used to clear ERROR BOX (red box lower left corner if you have errors). Errors usually happen for me when accidentally writing notes onto notes that are already written (doubled up notes).
Copy/paste icons
First select a note or group of notes. Then press COPY (double paper icon). Then touch somewhere on the timeline to move the orange vertical bar to a new measure. When you press the PASTE icon, a copy of your note(s) or pattern(s) are pasted at the new location. Can be used repeatedly to quickly paste groups of notes/patterns multiple times. Super easy once you get it.
I think that's about it. Anything else I missed?