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Imitate Guitar Techniques With MIDI Part 2 - Glissando (3-4 Semitones)

This post is part of a series called Manipulating MIDI: Setup, Sequencing and Secrets.
Imitate Guitar Techniques With MIDI Part 1 - Glissando (2 Semitones)
Imitate Guitar Techniques With MIDI Part 3 – Glissando (1 Octave)

Sampling, virtual instruments and MIDI keyboards give a lot of sonic options to today's music producer. But it's not always easy to reproduce the important nuances of musical instruments. Reproducing a lead guitar sound can be especially problematic - especially when it comes to string bending and sliding. In this tutorial, Oleg Berg continues his series of the best techniques to achieve those sounds.

Last time in Part 1 we spoke about the smallest glissando range - two semitones. Today, in Part 2, let's discuss another range of sliding - glissando for 3-4 semitones. We'll talk about it separately because some steps in this process are significantly different to those of a smaller glissando range. While certain actions are similar, I'll describe the differences in detail.

Here are the examples sounds we showed you last week. As you work through this series with me, you’ll learn to produce these sounds too.

Well, are you ready? Let’s start!

Note: This tutorial is good for any MIDI editor you use. I tried to make it as universal as possible, mentioning the commands, controllers, and window names of most programs – they may differ by name, but their functions are similar. I also explain the distinctions of programs with alternative system of numeric values. This makes the tutorial longer – but this way you can use it for your preferred MIDI editor. That is why you’ll sometimes find screenshots from several programs at one step. Enjoy!

Step 1

Let's start by playing a separate note for every fret the guitarist's finger reaches when sliding. Our glissando will be 3-4 semitones (4-5 notes). The sound we get is not quite realistic, and that's what we'll be correcting later. Don't forget to save the the initial file - we'll to refer to the copy later in order to know time of "Note On" events.

Step 2

In the previous tutorial when we spoke about 2-semitone sliding, the main note had pitchbend = 0. Pitch margin (Pitch Wheel Range = 2) was enough for us to shift the pitch we hear up or down two semitones while the note sounds.

Now when we want to shift the pitch four semitones up (for example, G-G#-A-A#-B), we'll have to use the entire range of the pitchbend parameter in the Piano Roll window, from -8192 to +8191.

In the beginning (when the parameter value is -8192, which is 2 semitones lower) the note's sound corresponds the note G. Similarly in the end, when value is +8191, 2 semitones higher, the sound must correspond the note B. In this case the main note will be A - all other notes' pitches will be changed to correspond the pitch of this one.

Therefore, change the pitch of all notes to correspond the main note pitch (in our example - A). By the way I would not recommend you to listen to the results of this in between process - the sound on this stage is far from what we want to hear.

Step 3

Now we'll combine the notes whose pitch was changed with the main target note. We'll use the Glue or Merge Tool for it - this way we avoid the sound effect of guitar string pluck - we need this effect for the first note only.

The pluck comes from the contact of finger and string, so we need it only at the beginning of our fragment. Other notes come from changing the length of string, so we combine the notes as if the sound was extracted only once in the very beginning.

Step 4

Make sure that on the VST instrument or sampler you use the value of Pitch Wheel Range = 2, which means that maximum shift of the pitch wheel will result in changing note pitch to 2 semitones. Most (but, unfortunately, not all) instruments allow to adjust Pitch Wheel Range (look at the images below). Many VST Instruments (samplers) make the value we need (2) a default setting.

I explained this process in Part 1, but I want to remind you again. If you for some reason couldn't find a way to change the Pitch Wheel Range, you can try another method. Select your guitar track and open the List Editor window (Event List). At the beginning of the track, enter 3 lines as in the image below (other columns - event time and MIDI channel number - may be different, of course).

There should be three controllers (not simultaneous, but one by one in small period of time) with numbers accordingly 100 (value = 0), 101 (value = 0), and number 6. The value of the last controller manages Pitch Wheel Range, in our case it has to be 2.

If you are lucky enough and your instrument supports specification General MIDI, it will recognize this message, "read" it, and the result will be our Pitch Wheel Range = 2. Of course, these messages should come before the notes to appear on the track. All these actions are possible for any pitch wheel range, for instance equaling 12 (an octave). However, the smaller the scale - the more precision for every graph. So, I recommend to choose PW range = 2.

Step 5

We repeat the fifth step from Part 1. In the Piano Roll window, at the left part for graphic editing, select Pitchbend (Pitch Wheel) from the dropdown list. This is the controller we need to help us change the pitch of note. Here is how it looks in different MIDI editors.

This tool will allow us to "create" new notes when there are actually no new notes, while the previous note is playing. Changing its pitch bend value will lead to increasing or reducing the pitch, as if the finger is moving to a different fret.

Step 6

This is the most important part of our process. We need to the draw points in the graphics editing section to assign the needed pitch to every fragment.

Remember that, for the horizontal axis, the points must precisely match the beginning ("Note On") of 4-5 notes taking part in glissando. The vertical axis shows the value of Pitchbend controller for every point (note). The main target note of the glissando fragment will have the Pitchbend Value = 0.

If we are sliding for four semitones, then we have five notes in our glissando - one at the beginning, and one for every glissando semitone. In this case, the main target note is the one lying in the middle of the range - the third one. Here the middle note is A - the one exactly in the middle between G and B.

The glissando range we want is three semitones. There are four notes in total - for example B-C-C#-D - like in the second glissando fragment in our example.

There are no strict rules here. You can choose either of two middle notes - C or C#. The difference between these two choices lies in pitch bend values we assign to points on the graph.

Step 7

Continue drawing points on the graph, corresponding to the notes in our glissando fragment. In the previous tutorial, when we spoke about a short 2-semitone glissando, we had just one middle note. Now we have two or three notes in the middle, depending on the sliding range we choose - three or four semitones respectively.

Remember, the horizontal x-axis coordinates of our points should correspond the beginning of the notes - here we can refer to a saved copy of our fragment we made in Step 1 to know the time values ("Note On"). Unlike Part 1, here the last note in the glissando will not have zero value, as the main note in this case will be in the middle of fragment.

If you want the correct numbers:

  • The pitchbend values for the fragment containing a glissando for four semitones (G-G#-A-A#-B) will be -8192, -4096, 0, +4096, +8191, with A as a main note with zero-value.
  • For a 3-semitone glissando (B-C-C#-D) values can differ according to the main note with zero-value we choose.
  • If we select second note as main one (C), pitchbend values for the fragment will be: -4096, 0, 4096, 8191.
  • If we choose the third note as main one (C#), the values for all 4 notes will be -8192, -4096, 0, 4096.

    Step 8

    While drawing the points in our last two steps, you may have had no difficulties in choosing maximum or minimum values (-8192 or +8191) and the zero controller value. However, when you draw points for semitone value (±4096), you may face some problems. I have already discussed this in the Part 1 of the tutorial.

    Don't worry if you have trouble precisely positioning the points. In reality, when a guitarist slides, an additional increase or decrease in string tension is inevitable - the surface of a fret board isn't perfect.

    But, if you are a perfectionist and you like everything precise, you still can assign the absolutely exact numeric value. Refer to the instructions and screenshots in Part 1, Step 9.

    Step 9

    Now we repeat this for the remaining fragments. The last example includes four such fragments - two up for 3 and 4 semitones, and two down for 3 and 4 semitones. For each of them make the similar graphic work using techniques described above. In cases when we need inverse glissando direction, simply change positive pitchbend values for negative, and vice versa.

    Step 10

    This step is for those who want an even more realistic result.

    When we imitate a slide longer than three semitones (as in the following example) the length of time the main note increases. The longer the glissando, the stronger the imitation of the natural fading of string vibration amplitude.

    When the guitarist moves his finger on the guitar neck pressing a string, the string receives small portions of energy whenever he reaches the next fret (especially when sliding up). The string rings longer than it normally would.

    In our case, the instrument does not care if its pitchbend value changes (or the value of any other controller, except those that alter volume). The sound fades naturally.

    Still we can imitate the energy portions on every new fret we just spoke about. With every increase in pitch we just add our sound a little volume. For this we need to choose the expression controller (Controller #11). Let's set this controller as a second one in the list of main parameters in the bottom part of the Piano Roll window on the left. All MIDI editors allow to do this.

    Now we can draw the volume increments, considering that the points where the pitch and volume increase must match. You can also copy the graph of pitch change and paste it in a new "expression" window. However, the vertical values of these points are up to you - here you'll need to experiment using your experience and preferences.

    However, your sound might act differently when it is a semitone higher - it may sound like it's louder as well. (Some sounds become brighter with a pitch increase.)

    In this case we need to reduce the note volume every time we increase its pitch. In every particular case, depending on physical parameters of instrument you use, you need to decide if an adjustment of the expression parameter is necessary, and whether it needs to be increased or decreased. Your taste and ears will help you make the right choice.


    Well, that is all for today! We learned how to imitate a realistic guitar sliding technique with MIDI keyboards in any MIDI editor for range of 3-4 semitones.

    Combining these techniques to imitate sliding, bending, whammy bar and plucking - combined with virtual adjustment tools - can give your virtual guitar track some unbelievable realism. When used wisely, it can sound just as realistic as live guitar playing, and the listener won't hear the difference. I've used this method thousand times and always heard many compliments to my guitarist =).

    Next time we'll discuss the widest range of sliding - an octave. I hope I gave you some useful tips and you've enjoyed it. Use it to create your own live guitar tracks with MIDI editor.

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