Add a "label" (text/numbers) to the left side of a staff.

I'm trying to do something like the numbered exercises you see in a method book, where each line (or several lines) of music has a number or letter to the left side of it.

Using Musecore 2.01 b25f81d

I tried to use a horizontal frame to do this, but you can't just double click it and add text you like do with a regular text frame.

I finally figured out after trying a bunch of approaches that you have to deselect the horizontal frame (if not you don't get the pop-up menu). Then right click on the horizontal frame and select Add->Text.

I think it would be more intuitive if you could just edit it after double-clicking. I am posting this mainly because I couldn't find any other place this was explained and thought it might help others if they run into the same thing.