Most recording software allows you to see and edit the midi notes you have recorded with the “piano roll” editor. This is a simple and logical method of visualizing sound and adjusting it to the desired outcome.
The name piano roll comes from a technology developed in the late nineteenth century. Originally, a piano roll was used to trigger the playback of a pianola or player piano by using a series of cutout dashes on a cardboard roll which would tell the mechanism what keys on the piano should be triggered.
How to Read the “Piano Roll” Editor
Back to the twenty-first century. When some midi data has been recorded on a keyboard connected to a computer, the recording software normally allows the data to be edited in the piano roll editor. (Shown in the diagram is the piano roll editor from Cubase, a recording software product from a company called Steinberg).
On the “y” axis is the pitch. Logically, the higher the position of the recorded event, the higher the pitch. You can see that the octaves are numbered starting from C to B.
On the “x” axis is time. At the top of the diagram, you can see the bar (measure) numbers. In this instance, each bar is subdivided into 4 parts which represent crotchet (quarter-note) beats. It is easy to see whether a note has been played early, on time or late. These notes can be recorded using a click track, which is a metronome that runs in perfect synchronisation with the recording to aid the performer to stay in time, vital if other instruments are added later. It’s an interesting exercise to see how well a student can synchronize to the click track to assess their timing skills. Of course, if the timing needs improving, all recording software will allow you to snap each note to the nearest rhythm line using a feature called “quantise” or by manually adjusting the start of the note with the mouse. As well as adjusting the “note-on,” you can also adjust the “note-off” either by “quantisation” or again, manually. As you can see in the above diagram, some notes are overlapping. I find it useful to show a student the piano roll, whilst listening back, so they can see where they need to improve. This has always been a very effective method of motivating improvement in their technique because they can not only hear but see where they are going wrong.
The final area I want to share with you in this article is the velocity lane. Put simply, it represents the volume of each note as shown by the bar graph at the bottom of the diagram. Notice how the volume of each note is color coordinated with red being loud, blue being quiet and the middle shades representing volumes between these two extremes. Again, listening back to a student’s performance will quickly help them to hear and see whether they have control of their fingers and a mastery of dynamics. If needed, it is easy to adjust the volume of individual notes or draw in crescendos and diminuendos.
Piano rolls are not just for piano and keyboard players! Midi drum kits and guitars are available to buy which will connect to a computer running recording software. The piano roll editor can then be used on these instruments too to see and edit note events.
2 Great Applications
Using the piano roll is a great teaching tool to help students hear and see where they are going wrong in their technique and a way to assess whether they are improving. Also, it provides a powerful way to perfect a recording that can later be converted into an mp3 file to share with family and friends which acts as a great motivator to students.