Fig. 1: Pitchmap lets you independently transpose the notes in a premixed, polyphonic recording to create new melodies and harmony arrangements.
Pitchmap promises polyphonic pitch transposition and correction in real time. This goes way beyond wholly shifting the pitch of a recording up or down to change its key, although Pitchmap can also do that. The plug-in can shift at once the pitch of all sounds in a mix that voice on the same fundamental musical note, transposing it up or down to another note. Do that on four different pitches, and you can make an ensemble that played a C mj6 chord, for example, sound like they played an F mi7 (using virtually any chord inversion you like). Pitchmap can also deliberately dish out synth-like sounds. I reviewed Version 1.1.4 of the Audio Units plug-in in Digital Performer 8.01, using an 8-core Mac Pro running OS X 10.8.2.
See Me, Shift Me
Pitchmap’s psychedelic GUI looks like what you’d get if a spectrogram mated with a piano. The pitches that comprise its audio-input signal are displayed as colorful blobs placed on an X-Y axis (see Fig. 1). The horizontal axis represents pitch, with progressively higher pitches depicted as you move from left to right. The higher the amplitude of each pitched event, the wider the associated blob. To help you quickly deduce which octave range you’re viewing, blobs are colored differently depending on the pitch range they fall into. The vertical axis is a timeline, showing only a few seconds of history from bottom to top.
A virtual keyboard runs horizontally along the bottom of the display. It serves as a grid that identifies each blob’s pitch as a musical note (rather than in Hz, like a spectrogram would). Each blob is delegated to the nearest pitch such that the display is essentially quantized; minor deviations from concert pitch aren’t displayed. The keyboard and blobs span only a three-octave range (in equal-tempered pitch), but the range can be scrolled higher or lower by clicking or dragging another virtual keyboard situated along the top edge of the GUI.
Immediately above each key in the bottom keyboard is a vertical pitch-mapping slider. Drag a slider up or down to likewise transpose all events voicing the associated note. The plug-in can’t cherry-pick discrete events to transpose, but you can adjust Threshold and Feel controls higher to avoid shifting non-pitched sounds such as drums, transients and noise. Keys in a third keyboard—vertically aligned along the right side of the GUI—light up to indicate the new pitch you’re transposing a note to. Pitchmap renders any pitch manipulations you make through to the end of the track, unless and until you make another pitch change.
The behavior of each pitch-mapping slider can be independently tailored in several different ways. It can transpose at once the same note where it occurs in all octaves or shift it within only the source note’s octave. Alternatively, the slider can be constrained to move a note toward the nearest octave, or the octave above or below the source note’s. This is your ticket to creating chord inversions and far-flung extensions. Pitchmap also includes a global tuning control that allows you to shift the entire program from A438, for example, to A440 (concert pitch)—or vice versa.
Fig. 2: All the notes in a mix are transposed in real time to the nearest notes in a C major chord, following MIDI Notes played into Pitchmap using a MIDI keyboard controller.
Pitchmap allows you to remove individual notes from a mix by muting them. You can also bypass processing below and above a specified note range; that helps when you don’t want kick drum and cymbals, for example, to be transposed.
The Threshold control sets how detuned a note must be from the plug-in’s input reference (for example, A440) in order to be processed. Setting the Feel control high preserves vibrato and glisses, while a low setting triggers your inner Cher. The Purify control amplifies (low setting) or attenuates (high setting) the noise component embedded in a note. You can even create polyphonic portamento effects of varying durations using the Glide control. Crank the Electrify control to produce unnatural coloration, or nosedive it to improve processing quality. Automation and MIDI
It would be daunting to dynamically automate so many parameters, so you may execute numerous and complex harmony changes throughout a song. For this reason, Pitchmap instead offers eight snapshots you can save and recall in turn to make sweeping changes instantly. Snapshots can be recalled by mouse-clicking on them or using DAW automation. I wish they could also be recalled using MIDI Notes; Zynaptiq is working on implementing this.
A highly innovative MIDI Map mode makes incoming MIDI Notes the sole target pitches for audio fed into the plug-in. This empowers you to dictate pitch transpositions on the fly by playing your MIDI keyboard. Each note in your audio track is automatically transposed to the nearest note played on your keyboard. (Three alternate key-edit modes affect to which octave range—or ranges—notes will be transposed, creating either small transpositions or long-haul shifts.)
I Took Notes
Instantiating Pitchmap on a full mix, I mapped the 3rd tone of the song’s native scale (D major) to the 4th note and flatted the 6th across all octaves, using the plug-in’s pitch-mapping sliders. As a result, the band voiced a D sus4 chord where it had played a D major in the original mix, and a G minor where G major had previously held court. An F#7 temporary modulation became G diminished. The lead vocal adapted to the pitch-mapped harmony arrangement, and a new, exotic melody was born. If you ever feel you’re stuck in a rut writing stock melodies and predictable arrangements, Pitchmap could be your ladder out of the trough.
If I wasn’t convinced that I liked some of my transpositions, I could temporarily bypass pitch mapping on a note-by-note basis (see the green keys in Fig. 1). On the downside, I couldn’t consistently make the vocal in a processed mix lock to its mapped pitch, the pitch-mapping occasionally created wildcard pitch shifts, and—even on wholesale transpositions up or down a whole tone—I sometimes heard both the source and destination pitches at once. The processed mix—especially the vocal—sounded phase-y and sometimes warbly and watery, making it unusable for commercial release.
Next, I activated the plug-in’s External MIDI and MIDI Map buttons, and I routed MIDI from my Roland A-37 keyboard controller to Pitchmap via a new MIDI track in DP. Playing chords on my A-37 forced all notes in the pre-recorded mix to the notes I was playing, instantly as I played them (see Fig. 2). Cranking the Purify control weeded out lingering unprocessed signal that was tainting the output and simultaneously made notes resonate beautifully, creating an angelic timbre evoking a synthesized organ. Remix engineers and DJs, this is your tool to make jaws drop.
Pitchmap is optimized to correct out-of-tune notes in very complex signals such as a full mix, which it did fairly well in my tests. It couldn’t correct intonation in an electric guitar vamp (a mono track), and it cut the signal level a few dB. I also tried removing a couple notes repeatedly sung on a full mix by selectively muting them on Pitchmap’s lower keyboard. The rogue notes were greatly attenuated but still audible, and I could hear their levels—along with the rest of the mix—pumping.
No other plug-in can do what Pitchmap can. It doesn’t sound pristine, but its polyphonic pitch-transposition capabilities are nevertheless truly groundbreaking.
The plug-in’s main applications are remixing, composition and sound design. The GUI’s note-based paradigm makes it operate the way musicians think—a plus—but the embryonic documentation leaves open sinkholes along the road to learning the plug-in. (A comprehensive manual is in the works.)
Version 1.5 should be out by the time you read this and will be a free update to current owners. It will support VST 2.4 (32- and 64-bit), RTAS and AAX Native formats on both Mac OS X and Windows. V1.5 will also sport the same preset manager as the company’s excellent Unveil 1.5 plug-in. I can’t wait!
Mix contributing editor Michael Cooper is the owner of Michael Cooper Recording in Sisters, Oregon (myspace.com/michaelcooperrecording).
PROS: Great for remixing, composing and sound design. MIDI control allows performance-oriented transpositions that astound. Snapshots can be automated.
CONS: Pitch transposition creates audible artifacts, sometimes unpredictable. Pitch correction and note removal don’t work reliably. Snapshots can’t be recalled via MIDI. Steep learning curve.
Instantiate Pitchmap on an overdriven electric guitar playing a vamp. Turn Pitchmap’s Threshold and Glide controls all the way down and activate the Strict button. Crank the Purify control to make the guitar sound like a cross between an organ and electric violin. Boosting the Electrify control enhances the electronic aspect further.