Introduction to MIDI and Computer Music:  Assignment 2

[home]   [syllabus]   [policies]   [assignments]   [help]   [links]

Assignment 2: MIDI Editing

What we're trying to do...

• Create a radically altered version of some existing music I give you.
• Learn how to copy and move groups of notes; automate volume, panning and effects level; use MIDI effects, such as echo and invert; work with continuous data; and make tempo changes.

What to turn in...

• A Digital Performer sequence file named "assign 2 final" or something similar. Drag this into your own folder on the Music Server.

  Verify that you've satisfied all the requirements by consulting the Assignment 2 checklist.

The basic process...

Do not use segments of a track from the original sequence that are longer than ten measures or so.

Before you begin work, study the Assignment 2 checklist, so that you'll know what all the requirements are. Read through the instructions given below, as well as the subsidiary pages linked from this one. Anywhere you see DO THIS, you'll know that it describes something you have to do as a requirement of the assignment.

Next, you should get familiar with the music I've provided. Play around with it, trying out different patches for the various tracks. Mute tracks to see what it would be like without them playing for some or all of the sequence.

Choose several aspects of the given sequence to use in your own version. These could include chord sequences, melodic motifs or phrases, rhythmic ideas. Think of ways to create a new context for original musical ideas. Rearrange the material using cut-and-paste techniques. Try doubling a melody by duplicating a track, and then assigning a different patch to the copy. You should also add tracks of your own to go with the existing music. You must use at least four tracks.

Use MIDI effects to change the sound of at least one track. Thoroughly mix the sequence, using the volume and pan controls in the Mixing Board, changing these over time for at least three of the tracks. Use controllers #91 and #93 to vary effect send levels. Adjust the tempo, and try changing the tempo over time.

How to go about it...

Here are the steps you should take to do the assignment.

1. You have a choice of MIDI sequences to remix. Grab them and decide which one you want to work on. Remember, it doesn't really matter whether you like your chosen sequence as is, because you're going to transform it into something else that is uniquely your own. In fact, if it sounds too much like the original, I won't think you've done enough with it.

   You can get the sequences from the "Resources" volume on the Music Server, inside the "Assign 2" folder in the "z361-resources" folder. Each sequence project folder is compressed, in a zip file. Copy this zip file onto the Desktop, and double-click it to uncompress.

2. Listen to the whole sequence, and try changing the patches assigned to each track, by using the pop-up menu in the DEFAULT PATCH column.

3. You can rearrange large sections of music using the Track Overview section of the Tracks window. Read about some techniques for moving and copying blocks of material in the Track Overview.

   Also, you can use the Cut, Copy, Paste and Merge commands in the Edit menu. This is a little trickier than you might expect. Read the instructions carefully before trying much of this. It's easy to lose data without realizing it if you don't understand how to use these commands.

4. Digital Performer lets you apply real-time, MIDI effects to each of your tracks. These effects manipulate the MIDI notes in a track — or generate additional notes — during playback. They do not change the note data in the track. (This is often called non-destructive, as opposed to destructive, processing, since the original data is left intact.)

   Using these effects, you can add echo, invert pitch, quantize rhythm, change velocity, "humanize" various parameters, and so forth. To use an effect on a track, open the Mixing Board, and choose an effect from one of the pop-up menus at the top of the Mixing Board. This is a little confusing, because these pop-up menus start out blank, as in the graphic below.

   

   If you don't see the upper part of the Mixing Board, you might need to scroll the view to the top.

   Just press and hold the mouse button on one of the arrows (circled in red above), and you'll see an effects menu.

   

   There are five vertically-arranged effect slots — called inserts — for each track. (These are dark grey; the light-grey slot above them is for invoking preset series of effects.) MIDI data flows from the top insert to the one below, and so on, down through all five. So if you have an Invert Pitch effect in the top insert, and an Echo effect in the one below that, the notes will be inverted first and then echoed. Switching the order of effects often gives you a different result.

   You can move an effect from one insert to another in the same track, or in a different track, by holding down the Apple key while dragging the effect name in the Mixing Board. Hold down the Apple and option keys while dragging to copy effect settings. Click the effect name while holding down the option key to bypass (temporarily disable) the effect.

   DO THIS: The project you turn in must use at least one MIDI effect.

5. Automation is the process whereby volume and panning, among other things, are made to change over time. (The term comes from large hardware mixing consoles, of the kind commonly found in recording studios. These have faders that can move by themselves, once the engineer's fader movements have been recorded by an on-board sequencer — a process known as automation.)

   NOTE: Before you do anything else, make sure event chasing is set correctly. Choose Setup > Set Event Chasing, press the Set All button, and then the OK button.

   To record automation...

   1. Open the Mixing Board window.
   2. Press the automation record-enable buttons for the tracks whose volume or pans you wish to vary. (These buttons turn red.)

      

   3. Play the sequence. (That's right: play, not record.)
   4. Wiggle the knobs and slide the faders, as you desire.
   5. Stop playing the sequence, and turn off the automation record-enable buttons, so as to prevent accidental changes.

   Now when you play the sequence, the faders and pan knobs will move, as long as the automation play-enable buttons are pressed. (These buttons turn green.)

   

   There's just one problem. You've effectively entered volume and pan controller data into your MIDI tracks — that's what the Mixing Board did for you when you wiggled its knobs. Now Digital Performer expects you to provide initial values for these controllers, at the beginning of any tracks that have changing automation. If you don't do this, the volume and pan at the start of playback may be wrong.

   One way to set initial values is to look at each track in the Graphic Editor. (See below). Make sure only one track at a time is visible. Locate the first event for each type of controller you've placed in the track. Click on the node for the event to select it. Either drag this to the beginning of the sequence, being careful not to change its value (vertical position), or look near the top of the Graphic Editor window for the list of information about the event, and change its start time to 1|1|000.

   DO THIS: The project you turn in must be thoroughly mixed, and it must include changing volume and panning for at least three of your tracks. For any track that contains any changing automation, you must insert initial values for the automation data — for example, by using the Insert button in the Event List window for a track.

6. Continuous data is data that changes smoothly over time. This includes MIDI controller change messages — like volume, pan and modulation — as well as pitch bend and aftertouch. You've already learned how to insert volume and pan data using the Mixing Board. Here are some other ways, which also allow you to insert the other types of continuous data.
   • Record continuous data into a track that already has notes. You can record pitch bend, joystick and knob data this way. To keep from erasing the existing notes when recording, be sure to press the Overdub button:  .
   • Use the Region > Create Continuous Data command.
   • Draw continuous data in the Graphic Editor window. To do this, first make sure that the only track visible (highlighted in the panel at the left of the window) is the one you want to work with. Then choose the pencil tool from the Tool palette (which you can show with the Studio > Tools command).

     

     Select the type of continous data you want to draw from the right-most menu at the bottom of the Graphic Editing window. Use the left-most menu to select the Lines method of displaying data, since that is easier to read. Click and drag in the area beneath the piano roll to draw lines. The image below shows the result of drawing a volume curve with the pencil tool.

     

   
   DO THIS: The project you turn in must contain some continuous data other than the volume and pan controllers you can create using the Mixing Board. Some examples that make sense for us: joystick up (controller #1), joystick down (#2), effects 1 send (#93), effects 2 send (#91), filter cutoff (#74), filter resonance or HPF cutoff (#71), attack time (#73), release time (#72), pitch bend, monophonic pressure (aftertouch). Make sure you understand the audible effect of these controllers.

7. The Conductor track contains tempo events, which define how fast your beats flow, as well as time signatures, which describe how many beats are in a measure. The Conductor track contains no notes (or MIDI events of any kind).

   You can make changes to the Conductor track by using the commands in the Project > Modify Conductor Track submenu. The Change Tempo command brings up a dialog where you type in the start and end times for a tempo change and specify the type of curve you want. When you press OK, new tempo events appear in the Conductor track.

   

   
   NOTE: You must set the Tempo Control pop-up menu in the Control Panel to Conductor track, or else Digital Performer will ignore the tempo settings stored in that track. Click on the arrow circled in red below to see the Tempo Control pop-up menu.

   

   
   DO THIS: Create at least one tempo change using the Change Tempo command. If you don't like the way it sounds, you can disable it by choosing Tempo slider from the Tempo Control pop-up. But leave the tempo change in the Conductor track so that I can see that you've tried it.

   ©2010, John Gibson