by Craig Anderton
When Sonic Foundry's Acid made its debut in 1998, it was a breakthrough product: Prior to that time, you couldn't simply drop a digital audio clip in a digital audio workstation track and be able to "stretch" both tempo and pitch in real time. (Propellerhead Software had introduced the REX file format four years previously, which also allows for time and pitch stretching. However, it was a specialized file format, whereas Acid could work with any digital audio file and "Acidize" it - more or less successfully - for stretching.)
Over the years other programs started to acquire similar capabilities, and as Sonic Foundry's fortunes declined, so did Acid's. However, Sony bought the Sonic Foundry family of programs in 2003, and started the rebuilding process. Acid's hard disk recording capabilities became on a par with other programs, and more recently, MIDI has been beefed up to where Acid can handle software synthesizers, MIDI automation, and external controllers with ease. In this article, we'll show how to add MIDI controller messages to MIDI tracks (for clarity, MIDI note data isn't shown).
Begin by selecting a MIDI track, then choosing "Automation Write (Touch)" from the Automation Settings drop-down menu. If you instead want to overwrite existing automation data instead of write new data, choose Latch (right below the Touch option). Latching creates envelope points when you change a control; if you stop moving the control, its current setting overwrites existing envelope points until you stop playback.
You'll see four control sliders toward the bottom of the MIDI track. If you don't see the controller you want, click on a controller's label; this reveals a pop-up menu with additional controller options, and you can then select the desired controller from this menu. In the screen shot, Modulation is replacing Aftertouch.
As with other programs (e.g., Cakewalk Sonar), it's not necessary to enter record mode to record automation data. Simply click on the Play button, then click and drag the appropriate controller slider to create an automation envelope in real time.
However, note that MIDI controllers can generate a lot of data. When computers were slower, this could sometimes cause problems because older processors couldn't keep up with the sheer amount of data. While this is less of an issue with today's fast machines, lots of tracks with controller data can "clog" the MIDI stream, particularly if you're driving external MIDI hardware rather than an internal software synthesizer.
Acid has an option that lets you thin the amount of controller data. To do this, click on the Envelope button to the right of the controller's slider, then select "Thin Envelope Data" from the drop-down menu. What's more, Acid offers automatic smoothing/thinning of automation data. To set this up, go Options > Preferences > External Control & Automation tab and check "Smooth and thin automation data after recording or drawing."
To add a point (what some other programs call a node) manually but still use the slider to set the value, choose the Pencil tool and click at the time where you want to add the point. Then, move the slider to change the newly-added point's value.
To add a point manually that can be moved in any direction, place the cursor over the automation curve until it turns into a pointing hand, then double-click to create a point. Click and drag on the point to move it. In this example, a modulation value of 27 is being entered at measure 1, beat 2, 192 ticks.
Another way to add an automation point is to right-click on the automation curve, and select "Add Point." Click and drag on the point to move it. Note that this same pop-up menu also lets you change the shape of the curve between points. In this example, Fast Fade has been chosen.
You can continue to add and edit automation until the automation "moves" are exactly as desired. So why bother? Because automation can add expressiveness to synthesizer parts by keeping sounds dynamic and moving, rather than static. The next step would be to add an external control surface, so you can create these changes manually using physical faders...but that's another story, for another time!
Craig Anderton is Editor Emeritus of Harmony Central. He has played on, mixed, or produced over 20 major label releases (as well as mastered over a hundred tracks for various musicians), and written over a thousand articles for magazines like Guitar Player, Keyboard, Sound on Sound (UK), and Sound + Recording (Germany). He has also lectured on technology and the arts in 38 states, 10 countries, and three languages.