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Vocal Harmony FAQ

  1. What is musIQ and how does it improve vocal harmony?

  2. Why was musIQ vocal harmony invented?

  3. So what exactly is wrong with the current generation of vocal harmony processors?

  4. What happens to my harmony when I play chords like the two-note E5, a rootless chord, or chord inversions?

  5. Will musIQ vocal harmony technology work for every song I play, no matter what strumming style or pattern I use?

  6. If I had a perfect MIDI guitar or a guitar-to-MIDI pedal, would I be able to make non-musIQ harmony processors (with MIDI support) sound as good as musIQ vocal harmony?

  7. If I sing off-key, will all my musIQ harmony voices be off-key as well?

  8. What happens to musIQ harmonies if I stop playing the guitar and sing a capella for a while?

  9. Does musIQ harmony work with other instruments besides guitar?

  10. Does musIQ harmony work if my guitar is slightly out of tune?

  11. Does musIQ harmony work with non-standard tunings (e.g. Dropped D, Dropped C, DADGAD, strings tuned a semi-tone down etc.) ?

  12. How does musIQ harmony respond to fret noise or other guitar playing artifacts that are not part of the song?

  13. How does musIQ-Alt mode differ from musIQ-Main mode?


What is musIQ and how does it improve vocal harmony?

Our musIQ technology “listens” to what you are playing and is capable of understanding the structure of your music. This patent pending technology has been used to improve vocal harmonies in two ways. The musIQ note detection engine is able to analyze complex guitar waveforms in real time and determine what notes are being played, while the musIQ harmony engine is capable of interpreting this note data in parallel with the pitch of the singer to determine the most musically correct harmony note to sing. The end result is the easiest to use and most musically correct harmony generation ever. See Vocal Harmony Made Easy for more details.


Why was musIQ vocal harmony invented?

musIQ vocal harmony technology was originally invented to give guitar player/singers an easy way to get great sounding vocal harmonies. Sure, the sound quality of harmony processors has improved greatly over the years, but we still heard comments like these over and over again:

  • "...it's too hard to figure out which scale / mode works with each song."
  • "...some harmonies just don't work no matter what key or scale I choose..."
  • "I don't know anything about MIDI and don't want to!"
  • "...scalic harmony didn't work so I tried MIDI - now the harmonies sound blocky and unrealistic."
  • "I don't want to learn to program and I can't tap-dance!"
  • "...I don't want to worry about stepping through programs on stage - it interferes with my performance..."

With musIQ vocal harmony technology, you can get natural sounding, musically correct harmonies simply by singing and playing your guitar as you normally do. We believe that this technology will bring vocal harmony processing to a much wider audience.


So what exactly is wrong with the current generation of vocal harmony processors?

Lots of musicians have made great use of vocal harmony processors over the past few years, but we believe the number of musicians who can benefit from and enjoy this technology is much larger. The main reasons preventing this in current harmonizers with musIQ are:

  1. The harmonies generated from MIDI note information (generally referred to as chordal mode or vocoder mode) are unsatisfactory because they tend to change pitch much less frequently than the input melody signal. As a work-around, it is sometimes possible to enter each harmony note individually, or else create a custom chord to match each input melody note, but these are both difficult, tedious, and often require extra interaction from the performer in order to step through the notes. Also, because the changes in the harmony notes are not triggered by the melody notes themselves (instead either a foot switch or MIDI sequencer is commonly used), the harmonies can sound unnatural and out of step with the melody line.

  2. When key and scale information is entered prior to starting the song, the harmonies can then be generated in step with the melody line (this is often called scalic mode). However, because the chord structure of a wide range of songs does not follow a set of rules that can be predetermined, the harmonies produced by this method often contain notes which are not musically correct because they are dissonant with respect to the accompaniment notes in situations where dissonance is unpleasant, thus limiting the usefulness of the harmony processing.

  3. The existing products are very difficult to use because they require musical information such as key, scale, scale-mode, etc. to be entered before harmonies can be generated (for scalic mode), or else they require each harmony note or corresponding chord for each harmony note to be entered manually and then triggered throughout the performance.


What happens to my harmony when I play chords like the two-note E5, a rootless chord, or chord inversions?

To answer this question, it is first important to understand that musIQ harmony is not generated by simply recognizing a chord and then using some sort of table look-up to find a harmony note. This type of approach would be extremely sensitive to power chords, rootless chords, and similar chord patterns. Our technology creates harmony lines by analyzing the current song over many time scales. At the longest time scale, the accompaniment and melody notes give rise to what is usually refered to as the "key and scale" of a song. At the shortest time scale, the current chord being played dominates. Between these two time scales you may find anything from several bars that go outside of the song's main mode, to entire choruses that are in a completely different mode. Because of the multi-timescale analysis, we can avoid having to rely only on the extremely localized note patterns (as is evident in the blocky sound typical of MIDI chordal mode in existing harmonizers). At the same time, we can avoid being fooled by localized mode changes - a common problem with scalic modes.


Will musIQ vocal harmony technology work for every song I play, no matter what strumming style or pattern I use?

For every song? Well...in a word...no! In order to generate the best harmonies possible, it is important to have a rich enough bed of information over which to create the harmony voicings. We have tested this technology over a wide range of playing styles and have found that the vast majority of styles work well. However some syles - for example those featuring extremely sparse strumming patterns - may not produce the harmonies you are after. But when compared with the huge number of songs that don't work with the existing harmony products, we think you'll be pretty happy with the overall robustness of musIQ harmony!

But this brings up an important point: the most interesting thing (and somewhat unexpected!) that came out of our extensive trials was how quickly players learned to make slight changes to their guitar playing to get the harmony sound they wanted for the few songs that didn't do what they expected. For example, one player wanted the harmony to go to a 7th, but realized that he was playing the major chord. Simply by switching to a 7th, he got the harmony he wanted. We saw this happen enough to realize that the player was learning to control the technology with his guitar - all in all a much better user interface that in the past since no new skill was required!


If I had a perfect MIDI guitar or a guitar-to-MIDI pedal, would I be able to make non-musIQ harmony processors (with MIDI support) sound as good as musIQ vocal harmony?

No. The musIQ harmony engine was designed from the ground up to give the most natural sounding harmonies ever. There are several things that make musIQ vocal harmony technology superior to pre-musIQ harmony processors or guitar-to-midi pedal solutions. we look at the lead vocal and guitar accompaniment as a coherent musical unit in order to get better voice leading and avoid blocky sounding harmony. As well, we've put considerable effort into modelling the way guitar players strum in order to get the best possible information to drive harmony generation.


If I sing off-key, will all the musIQ harmony voices be off-key as well?

Yes and No. If you sing slightly off-key, and the notes you are singing change rapidly, then the harmonies will be slightly off-key as well. However, as soon as you hold a note for a reasonable period of time, the harmony voice will quickly move to be in-tune. This helps you sing better because you hear the harmonies singing the correct notes. However, if you sing way off-key, then musIQ may get confused about what note you are intending to sing, and may pick the wrong harmony note.

By the way - the reason for allowing the harmony pitch to follow the short-term pitch changes in your singing is to increase the naturalness of the harmonies. Without this, harmonies tend to sound like an synthesizer rather than a real person.


What happens to the musIQ harmonies if I stop playing the guitar and sing a capella for a while?

In general musIQ harmony will work fine if you do this. musIQ will use the guitar chords you have been playing before your a capella section to make good harmony choices that will fit in with your song. If you want to have more control over the harmonies that are generated, then you can mute the guitar after the musIQ harmony engine and strum chords to direct the harmony voices.


Does musIQ harmony work with other instruments besides guitar?

Yes, but ... musIQ harmony was designed to work with guitar, both in terms of the note range, and guitar playing styles. However, if you use another instrument with the same note range as guitar, musIQ harmony will probably work fairly well, but this was not a design goal and it has not been tested very thoroughly.


Does musIQ harmony work if my guitar is slightly out of tune?

The musIQ guitar note detection works best if your guitar is tuned accurately to a scale based on a 440Hz reference. However, it is very tolerant to your guitar being slightly out of tune so you don't have to worry excessively about this.

And don't worry! The actual harmony pitch does not depend on how well your guitar is tuned, so if your guitar tuning drifts a bit, your harmony notes will NOT drift as well. Of course, if your guitar goes so far out of tune that the note detection starts detecting the wrong guitar notes, the wrong harmony notes may get chosen. But if your tuning gets this bad, please stop singing and tune your guitar because the wrong harmonies aren't your main problem!


Does musIQ harmony work with non-standard tunings (e.g. Dropped D, Dropped C, DADGAD, strings tuned a semi-tone down etc.) ?

Yes. musIQ harmony works with any guitar tuning as long as it is based on a Chromatic (i.e. 12 note) equal-tempered scale with a 440 Hz reference. musIQ harmony does not support micro-tonal scales.


How does musIQ harmony respond to fret noise or other guitar playing artifacts that are not part of the song?

A lot of effort was put into modelling exactly how guitar players play so that fret noise and other unintentional artifacts would not cause poor harmony note choices. This process is not perfect so you will always get the best results if you play guitar cleanly, but you should find the harmony voice generation fairly tolerant of guitar playing artifacts.


How does musIQ-Alt mode differ from musIQ-Main mode?

The musIQ-Main mode is designed to pick good choices for harmony notes over the widest possible variety of chords and melodies. In order to meet this objective, it is sometimes necessary to pick a “safe” harmony note in a case where an alternative harmony note is more desirable. The most common example of this is when the melody is singing the 5th of a chord, and a 3U voicing is selected. To look at a specific example, consider a melody sequence of F# – G – A over a D major chord. For the 3U voicing, the musIQ-Main mode will typically choose a harmony sequence of A – B – D. The musIQ-Alt mode, on the other hand, will typically choose a harmony sequence of A – B – C. Note that the “D” is a safer choice and will always sound good. But choosing a C for the last harmony note follows the melody more closely and in some situations may be exactly what you want. It’s probably best just to stick with the musIQ-Main mode, but try out musIQ-Alt if you encounter a situation like this.

Of course, another way of getting that C might be to play a D7 chord instead of Dmaj, so you can always use your guitar to influence the harmony notes as well!

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