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Opcode Software Tips

Tips & Tricks
Published July 1997

Greg D'Alessio of Opcode Systems offers some hints, tips, and advice for Mac users running Vision, Studio Vision Pro, and Overture software.

At Opcode Systems we receive a wide range of questions from our users, concerning everything from basic troubleshooting to specific features of our applications. The following tips and setup instructions answer a few of the most commonly asked questions, but there are also a couple of more sophisticated, 'high‑end' techniques to help you get the most out of Vision, Studio Vision Pro, Overture and OMS, the Open Music System, running on a Macintosh.

MIDI Communication Problems

A great many problems with MIDI software revolve around input from a controller not reaching the software, or output from the software not getting to a MIDI device. These are MIDI communication errors and probably have one of several causes:

Your OMS Studio Setup is improperly configured or not current.

  • Go through your Studio Setup very thoroughly to make sure that all of your devices are properly defined and depicted (Figure 1). Pay special attention to whether the ins and outs (virtual patch leads with arrowheads) to all device icons reflect the physical patch cords of your actual studio. Also, double‑click on each device icon to open up its MIDI information window and check that it's set up to receive on the channels to which you want to send MIDI; make sure that you've established whether it is a controller and whether it is multitimbral. This is all especially useful if you haven't been using the program for a while, or if you've opened up an old Studio Setup in a later version of the program, as it's easy to forget about any changes you've made in your studio that might not be reflected in your OMS Setup.
  • Make sure that there's a diamond by the name of your Setup in the title bar to indicate that it is the current studio Setup. If there isn't a diamond, choose Make Current from the File menu.
  • Go to the Studio menu and select Test Studio. When you move the cursor over one of your device icons, it should turn into a note. (If it doesn't, check back in the Studio menu and make sure there's a check mark next to Test Studio.) Single‑click on the device icon. You should hear random bursts of MIDI signals from your device — and these can be quite loud, so make sure your volume is down! Now go over to any controller keyboard that you have and play a key. You should hear a voice in your Macintosh say "MIDI received", and see the input arrow in the Studio Setup flash.

Your physical studio is not set up correctly.

  • Check and double‑check that all devices have the desired MIDI Ins and Outs going to the opposite kind of port (In to Out/Out to In) on your MIDI interface.
  • If the communication problems are only with one device, try substituting different MIDI cables connected to it, to see if you have a bad one.
  • If the problem is only on playback, check that the device's volume is turned up, and that any mode or other front‑panel settings that allow it to send or receive MIDI are correctly configured.
  • Try using a different serial cable from your Mac to your MIDI interface.

Extension Conflicts

A very large percentage of the problems people have with their software on Macintoshes results from a conflict between various system extensions. Extensions are programs or parts of programs that are automatically loaded into RAM when you turn on your computer — you will see them as little puzzle‑piece icons at the bottom of your screen when you boot up. In general, it's best to run with as few extensions as possible to avoid any conflicts.

Macintoshes with system 7.5 or later have an Extensions Manager control panel, where you can turn off extensions so that they won't be loaded into RAM when you restart; on Macs with earlier systems you can achieve the same result by dragging extensions from the Extensions folder (in the System folder) to any other folder on your computer — though creating a special Disabled Extensions folder and placing it in an obvious locale, such as your desktop, is highly recommended. There are also several commercial start up managers, such as Now Utilities, which will perform this same task.

When you're using Opcode software, you actually need only two or three active system extensions. The first of these is always necessary, and that's the Open Music System (OMS). If you're using MIDI only, without any digital audio, you can boot up your computer with only OMS enabled as a system extension and run all Opcode applications fine. If you're going to be doing any digital audio, you'll need either Apple's Sound Manager extension (recent operating systems have this built in) or Digidesign's Digisystem init, if you're using any Digidesign audio hardware. In addition, if you're using a card or interface that requires an extension — Digidesign's Samplecell card, for example — you'll need that as well. You might also need your printer driver if you intend to print something from an application.

Separating A Drum Machine Track Into Multiple Tracks

Suppose you record a track of drums into an Opcode sequencer from a drum machine or other MIDI device which has different sounds assigned to different notes, and you want to edit the volume or other parameters of the individual sounds separately.

  • Make sure that the track is selected in the tracks window (the dot at the beginning of the track will be a triangle).
  • Open the Select by Rule window — Edit then Select or Command+[E] — and choose Note in the decryption pop‑up by clicking and holding on Events (see Figure 2). Then select 'is' from the description conditions (click and hold on the word Any in the description area), and either click and hold on the note name and select the note corresponding to the patch you want, or single‑click on the note name and play the appropriate note on your keyboard controller, then hit Select. (If you have the drum machine set as the Thru Instrument by the keyboard icon, you will be hearing the actual drum sound as you do this.)
  • When you open an edit window (list, graphic or notation) the selected notes will be highlighted (Figure 3). Cut them (by choosing Cut from the Edit menu or pressing Command+[X]), then select a different track in the tracks window and paste the notes you selected in the main track into the new track (using Paste from the Edit menu, or Command+[V]).
  • Now assign this track to the same patch and you will have separated out a given drum sound which you can then control (volume, pan, velocity and so on) separately from the rest of the sounds in the original track (see Figure 4 on page 98).

Replacing MIDI Events With Audio Events

Obviously, this tip is only relevant to MIDI + Audio sequencer owners! This is what to do if you have a sequence with a MIDI drum track and you want to replace it with some sampled drum sounds that you've recorded to your hard drive.

  • Separate the different MIDI notes in the drum track, as above.
  • Import your drum soundfile into Studio Vision (Option+[H]), select it, and copy it — this writes it to the clipboard.
  • Open the Graphic edit window for the MIDI drum track and select the MIDI notes that you want to substitute with the audio file.
  • Open the Substitute window in the Do menu. Click the 'Replace each selected event with the contents of the clipboard' radio button, and hit Substitute. Studio Vision will then put the audio file drum sound from the clipboard into the sequence in place of each MIDI note.
  • Repeat this procedure with the other MIDI drum notes and different audio files and you can create a new audio drum part in place of the original MIDI file. Once you have substituted audio files for all the MIDI tracks, you can select all the audio tracks and choose Mix audio from the audio menu. This will create a single track of all the audio files which will play back well from hard disk.

Recording From An External Sequencer

Imagine that you've created songs in an external MIDI device's built‑in sequencer and want to record them into Vision. Here's what to do...

  • Go to the Setups menu and check 'Input Map Enabled'.
  • Open the Input Map Window and choose 'Make one line per channel' from the pull‑down menu in the title bar.
  • In the Options menu, set the Receive Sync mode to either External Beat Clock or MIDI Time Code, depending on what kind of timing data your external sequencer actually sends. Set the Receive Sync Device to be the external sequencer that's sending the data — make sure that the device has been defined as one that sends sync in your OMS Studio Setup. If you have a Studio 4 or MIDI Time Piece interface/patchbay, choose that instead. Note that in the 3.5 versions of Vision and Studio Vision Pro, there's a new Sync Options window which consolidates most of the above functions.
  • Open the Record filter window in the Setups menu and choose All Except, then click the check box for Tempo. Filtering the Tempo data will allow for more accurate transcription when recording multi‑channel data.
  • Put the sequencer in Wait For Note mode, record‑enable a track, click the Record button (or hit the tab key) and begin playing your sequencer. When the external sequencer has finished playing, hit Stop (or the return key).

The data from your external sequencer will be recorded all in one 'multi' track. If you select this track and choose Separate Multi Track from the Edit menu, each channel will be placed in its own track and you can assign them to different MIDI devices and patches, and edit the data exactly as if you had created the sequence in Vision itself (see Figure 5).

Assigning MIDI Channels To Device Modes

Many MIDI devices access their patches in different modes: Patches, Performances, rhythm, and so on. It is an inherent limitation that you can only send to one mode at a time for any given MIDI channel. You can, however, set up Vision so that certain channels of the device will always be set to certain device modes — so that, by switching between various MIDI channels, you can access all the different modes on your device at any given time.

  • From the Windows menu in Vision or Studio Vision Pro, or the OMS Names window in the Options menu of Overture 2.0 or later, open the Names window.
  • Select the device that you want to reassign, go to the Names menu and select Show Channels. Studio Vision will then list all the various channels of the device in the names window.
  • In the Device Mode column, assign different channels to different modes.

At this point, if you go to the Trumpet icon in the control bar you will see different names when you select different MIDI channels.

Creating A Patch‑Name List

If you get a new synthesizer and there is not yet a Librarian module in Galaxy (Opcode's editor/librarian software) or a patch name document in OMS for it, you can create your own patch name list in Vision, Studio Vision Pro or Overture 2.x.

  • Define the device in your OMS Studio Setup and run a Test Studio to make sure that the device is sending and receiving MIDI signals.
  • Go to the Names window in the Windows menu of Vision or Studio Vision, and single‑click on the icon for your device in the Device column — if it's not there, check that the OMS Studio Setup has been made current.
  • Double‑click on the Patch Name Document column for the new device; this opens up the Patch Name Document window. Single‑click on the patch name column for the first patch number (which defaults to 0). This will highlight the field and allow you to type in the name for that patch number.
  • Repeat this procedure for all the patches you want to list. If you have multiple banks in your device, you can configure them in the Add Bank window in the Patches menu. When you've entered all the patch names, click OK and then save the document. This will take you back to the Patch Names from OMS window.
  • At this point you can Subscribe to this document in the Names menu as though it was loaded from a synthesizer: select the device in the Names window and choose Subscribe from the Names menu — select your new Patch document and hit Open. Once you've done this, the names you entered will be available to you in the patch name window next to the Trumpet icon.

Harmonising A Vocal Line With DSP

Suppose you have a vocal line that you want to sweeten up with a little close harmony. Rather than call in a bunch of back‑up singers, you can use either the pitch‑shifting or Audio‑to‑MIDI and MIDI‑to‑Audio Digital Signal Processing (DSP) functions in Studio Vision to get the same results in a fraction of the time.

PITCSHIFTING

If you want to harmonise at a set, parallel interval, the best DSP function to use is Pitch Shift.

  • Select the vocal line that you want to harmonise in the Track Overview window and copy it to a new track.
  • Open the Pitch Shift DSP window and choose the interval you want to transpose the line to. Check Maintain Voice Character (version 3.5 only) to avoid 'munchkinising' the sound, and hit OK. This will create a new sound file that's a transposed version of the original (see Figure 6).
  • With the original file on one track and the transposed version on another, on playback you will get an incredibly tight, smooth vocal harmony.

AUDIO‑TO‑MIDI & MIDI‑TO‑AUDIO

If the line you want to use as harmony isn't a straight parallel transposition of the original, you should use the Audio‑to‑MIDI DSP function.

  • As before, select the vocal line in the Track Overview window and copy it to another track.
  • Open the Audio‑to‑MIDI window in the DSP menu. You'll want to choose the appropriate template for the sound file you are using, and set the range as close as possible to the actual range of the soundfile for faster processing (see Figure 7).
  • Once the MIDI notes have been generated, you can edit those notes (in terms of pitch level or pitch bend) in any way you want, as long as you don't add or subtract notes from the original. (You can play the MIDI notes back along with the audio to test the line — see Figure 8.) Select the MIDI notes and audio file in the Track Overview window, and choose MIDI‑to‑Audio in the DSP menu. Choose the functions you want to process and hit OK. Studio Vision Pro will take the changes you made to the MIDI notes and apply them to the original sound file. This produces an audio event with the same sonic characteristics as the original but a completely new melodic shape. You will probably want to delete the MIDI notes so that they don't play back with the audio.

Corrupted Preferences

Occasionally, one of the files that an application uses when it's running can become corrupted, usually resulting in small glitches or strange performance in a previously functioning program. If these files are trashed or moved when the program is not running, they will be recreated afresh when you re‑launch the application.

For Vision, Studio Vision Pro or Overture, the file is in the Preferences folder (inside the System folder) and will be called 'Vision Preferences' (or 'Prefs'), or 'Studio Vision Preferences', and so on. If you develop an odd or anomalous problem in the application, simply quit the program, drag this preferences file into the trash and reopen the program. You will have to reset a few of your application's parameters — the Metronome's assigned MIDI note, for example.

Web Link

You can find more suggestions like the ones in this article at Opcode's web site; go to www.opcode.com and use the 'Support' link to get to them.