2 – Introducing the TASCAM TA-1VP Vocal Producer

•• Really Easy To Use  No scrolling though endless menus to find the parameter you want. Virtually every major function is only a single button press away.

Auto-Tune Pitch Correction

In 1997, Antares first introduced the ground-breaking Auto-Tune Pitch Correcting Plug-In for ProTools™ (eventually followed by most other plug-in formats). Here was a tool that actually corrected the pitch of vocals and other solo instruments, in real time, without distortion or artifacts, while preserving all of the expressive nuance of the original performance. Recording Magazine called Auto-Tune a “Holy Grail of recording.” And went on to say, “Bottom line, Auto-Tune is amazing… Everyone with a Mac should have this program.”

The TA-1VP's Auto-Tune module is a licensed hardware implementation of Antare's Auto-Tune Evo pitch correcting software. Like Auto-Tune, the TA-1VP employs state-of- the-art digital signal processing algorithms (many, interestingly enough, drawn from the geophysical industry) to continuously detect the pitch of a periodic input signal (typically a solo voice or instrument) and instantly and seamlessly change it to a desired pitch (defined by any of a number of user-programmable scales).

A little bit about pitch

Pitch is typically associated with our perception of the “highness” or “lowness” of a particular sound. Our perception of pitch ranges from the very general (the high pitch of hissing steam, the low pitch of the rumble of an earthquake) to the very specific (the exact pitch of

a solo singer or violinist). There is, of course, a wide range of variation in the middle. A symphony orchestra playing a scale in unison, for example, results in an extremely complex waveform, yet you are still able to easily sense the pitch.

The vocalists and the solo instruments that the TA-1VP is designed to process have a very clearly defined quality of pitch. The sound-generating mechanism of these sources is a vibrating element (vocal chords, a string, an air column, etc.). The sound that is thus generated can be graphically represented as a waveform (a graph of the sound’s pressure over time) that is periodic. This means that each cycle of waveform repeats itself fairly exactly, as in the periodic waveform shown in the diagram below:

Because of its periodic nature, this sound’s pitch can be easily identified and processed by the TA-1VP.

Other sounds are more complex. This waveform:

is of a violin section playing a single tone. Our ears still sense a specific pitch, but the waveform does not repeat itself. This waveform is a summation of a number of individually periodic violins. The summation is non- periodic because the individual violins are slightly out of tune with respect to one another. Because of this lack of periodicity, Auto-Tune would not be able to process this sound.

Some pitch terminology

The pitch of a periodic waveform is defined as the number of times the periodic element repeats in one second.

This is measured in Hertz (abbreviated Hz.). For example, the pitch of A3 (the A above middle C on a piano) is traditionally 440Hz (although that standard varies by a few Hz. in various parts of the world).

Pitches are often described relative to one another as intervals, or ratios of frequency. For example, two pitches are said to be one octave apart if their frequencies differ by a factor of two. Pitch ratios are measured in units called cents. There are 1200 cents per octave. For example, two tones that are 2400 cents apart are two octaves apart. The traditional twelve- tone Equal Tempered Scale that is used (or rather approximated) in 99.9% of all Western tonal music consists of tones that are, by definition, 100 cents apart. This interval of 100 cents is called a semitone.

How Auto-Tune detects pitch

In order for Auto-Tune to automatically correct pitch, it must first detect the pitch of the input sound. Calculating the pitch of a periodic waveform is a straighforward process. Simply measure the time between repetitions of the waveform. Divide this time into one, and you have the frequency in Hertz. The TA-1VP does exactly this: It looks for a periodically repeating waveform and calculates the time interval between repetitions.

The pitch detection algorithm in the TA-1VP is virtually instantaneous. It can recognize the repetition in a periodic sound within a few cycles. This usually occurs before

the sound has sufficient amplitude to be heard. Used in combination with a slight processing delay (no greater than 4 milliseconds), the output pitch can be detected and corrected without artifacts in a seamless and continuous fashion.

The TA-1VP was designed to detect and correct pitches up to the pitch C6. If the input pitch is higher than C6, the TA‑1VP will often interpret the pitch an octave lower. This is because it interprets a two cycle repetition as a one cycle repetition. On the low end, the TA-1VP will detect pitches as low as 42 Hz. This range of pitches allows

8 TASCAM TA-1VP