Adding Notes with the Mouse
There are two quite different ways to add notes with the mouse in Composer. The first way is the most obvious way: point and click. Choose a note duration value from the Note Palette, or use a keyboard shortcut such as "4" for quarter note and "16" for 16th note. Then click the mouse where you want it to be added. This point-and-click method for adding notes "feels good" because as you move the mouse around, the notes snap to the grid of a Beat Ruler, which lets you know with more confidence where the note will be added when you click the mouse.
The second method of adding notes with the mouse is not so immediately obvious because, for one thing, you may not have seen this feature in other music programs: the Sequential Note Entry Method. With this method, the duration of a newly added note is determined by where you add the next note. Initially, the duration of a newly added note extends to the end of its measure, and also to the end of the next measure. This is probably not the duration you intend for the note. However, as soon as you add the next note after the first note, the duration of that first note will be changed so that it ends where the next note begins. The term "sequential" is used here to suggest how one would add notes sequentially, from left to right, in the score, where each note usually follows the previous. (It's easy, however, create chords with multiple notes, as well as to include rests between notes.)
TIP: Many Composer users tend to initially overlook this useful Sequential Note Entry Method, because the Note Duration Palette draws their attention first, and they quickly develop the habit of point-and-click for adding notes. However, many users have discovered the Sequential Note Entry Method with delight and wish they had been using it all along. We suggest that you briefly try it out so that you can decide whether it suits your working habits.