Select all equal notes/events only

hi, thanks for asking

you should just rubber-band (lasso) over the piano-keyboard on the left side; if keys are too tiny, then vertical zoom-in might help a little.

hth.
cheers

Worth noting here is that your "Select Mode" would need to be set to "Edit Draw". Personally, I've never been a fan of clicking on things to switch through these 3 modes and have setup 2 keybindings in order to speed up common operations.

Edit/Select Mode/Edit Off = s
Edit/Select Mode/Edit On = w

This way, I can quickly enter (select) or (write) mode with my left hand while operating the mouse as needed with my right. The left hand being able to toggle through these common modes like this makes sense since it can also easily reach the Shift and Control keys for zooming. I've actually found I don't need (or miss) Draw Mode at all using this approach. In the rare cases where I do want to select all notes of a corresponding MIDI Note #, I quickly zoom all the way out, press 's' and can then quickly lasso everything I need. There's also the "reversal" operation (I can't remember what's it's called right now) that selects the exact opposite of everything that's been selected. That's come in handy on a few occasions and if I used it more frequently, it'd be assigned to a keybinding as well.

Continuing this "map all the everyday operations to the left hand" approach, I've also configured these:

Delete = d
Undo = z
Select All = a

The above 2 are also setup in the Arranger view (remember, these keybindings are maintained independently) in addition to these personal game changers:

Copy = c
Paste = v
Unlink Current Clip = b (this is so important to avoid unintended destruction since clips are linked by default!)
Merge clips = g

There are more keybindings I've added to boost productivity but I can't look them up right now.