P = Draw tool (Pencil)
Some keyboard modifiers apply only while Pencil tool is in use

Shift-click to create a MIDI note the size of current Snap setting
or Click+drag to lengthen the MIDI note to the desired size

B = Brush tool [Shift + Option + Left-click?]

TEMPORARILY switch from pencil tool to Hand Tool: Shift + Right-click OR Shift + Control + Left-click

D = Delete tool OR Right-Click and drag over clips or MIDI notes to Delete

T = Mute tool
temporarily use Mute Tool: Double-Right-click + hold + drag over any items in the timeline to mute/unmute them [cursor turns into an X]
Mute selected: Option M
unMute selected: Shift+Option M
Hold “T” key + click and drag cursor over top of MIDI notes to Mute them
Hold “Option key + click onMIDI notes to Mute them ?
S = Slip tool

C = Slice tool/Cut)
(hold Shift to snap cut-line to lines or snap setting (click on clips)

Temporarily use Slice tool (*begin the Slice above or below and drag across a clip

• [righthand] Shift key + Left-click – cut using vertical line, snap to lines
• [righthand] Shift key + Right-click – the smaller portion of the cut clip will be deleted
  (*adding Option orients the cut-line vertically and disables snapping)

Slice (Cut) tool: C
*Quick switch to BLUE LINE Slice Tool: *righthand Shift key + Left-click + drag overtop of a playlist item [*don’t start the drag ON the item]
*Quick switch to RED LINE Slice(+Delete) Tool: [righthand] Shift + Right-click + drag overtop of a playlist item [automatically deletes the smaller portion of whatever is sliced/cut.]

E = Selection tool
TEMPORARILY use Marquee selection tool… Cmd-click + drag to Marquee select items in the playlist/piano roll
Select additional playlist items… Cmd+Shift click for individual items (clicks toggle between select/unselect)
Cmd+Shift click+drag to marquee select)

Selection tool: E [right-click?]
TEMPORARILY switch from pencil tool to…
TEMPORARILY switch from pencil tool to… Cmd Shift-click + drag to select additional items in the playlist

Z = Zoom tool
TEMPORARILY switch from pencil tool to… Cmd Right-click + drag marquee select an area to zoom to fill the Playlist window.
Command Right-click (Playlist or Piano Roll) – toggles between current window view and zoomed in view revealing ALL clips/notes
Zoom horizontally – Command scroll
Zoom vertically – Option scroll (*does not work in Piano Roll)
Zoom in – Page Up
Zoom out – Page Down

Y = Playback tool – plays midi notes or clips when cursor is hovers over them OR Option Right-Click