Source: https://www.image-line.com/fl-studio-learning/fl-studio-online-manual/html/pianoroll.htmMagic lasso - The Piano roll Menu > Select > Magic lasso option must be selected. Move your mouse pointer in a loop that encloses the notes you want to select (no clicking required, it's 'magic' remember). Make sure you have no notes selected before you perform the lasso action (Right-Click the empty Piano roll to deselect all notes and make another selection).
But the piano roll gives no visual feedback until the loop is completed and the notes become selected and change color. Is this normal behavior, or do I just have some setting turned off? I would like to be able to see the loop as I draw it.