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Producing Realistic Guitar Strumming Effects Using Creator/Notator

Tips & Techniques
Published June 1994

Sean Kenny is an experienced programmer, and has devised a method for emulating guitar strumming using a sequencer. Though the methods described here relate specifically to C‑Lab/Emagic Notator and Creator, they could be adapted for use with other sequencing packages.

Having been a dedicated sequence programmer and C‑Lab (Emagic) user for the past five years or so, I've always found one of the most difficult instrumental imitations to recreate from the keyboard has been the guitar — especially strummed guitar. Numerous hardware alternatives have been introduced, ranging from pick‑ups mounted on guitars to free‑standing devices which convert chords played on the keyboard to guitar chords. Unfortunately, these alternatives are not cheap, and certainly the pick‑up based pitch‑to‑MIDI converters offer only a limited degree of success, often with perceptible delays when playing the bottom strings on the guitar (another problem with the latter being that you have to be able to actually play the guitar!). The main difficulty in trying to record the guitar track from your keyboard can be more graphically illustrated as follows; using the guitar chord A Major (bar chord; guitarists see chord chart) the composite notes laid out on the keyboard are as shown in Figure 1.

Playing this chord on the keyboard is not a problem, except that it requires two well‑stretched hands and it is difficult to play the chord many times in rapid succession, as would be needed to recreate a strumming effect. If only we could trigger these six notes by playing just one note on the keyboard... Well, if you're a Creator or Notator user, you can!

Simply by using the Ghost Of feature (found in the track parameter box on the main page) in the way described below, some pretty convincing results can be achieved. First, it is important to define exactly what a Ghost track is. A Ghost track contains no data whatsoever. Its function is to play the data of a source (master) track, but subject to its own track parameters, and without actually copying any of the source track data to itself. It's a sort of realtime track copy facility, in that the Ghost track will contain no MIDI events. The purpose of this function, normally, is to save data and time where, for example, two different sounds need to be layered to form one sound — with the added advantage that any changes made to the source (master) track will be automatically duplicated by the Ghost track. A Ghost track is formed simply by entering the source track's pattern number and track number in the Track Parameter box of any empty track, as in Figure 2, right.

By using Ghost tracks to create multiple copies of one track, each of these copies can then be individually transposed to create the harmonic intervals of a chord. For example (using our A Major bar chord from above); Tracks 1‑6 are set to Ghost Track 16 (we will call this our master track), and the note A1 is then recorded into track 16 from the keyboard. The result is as follows;

By creating six Ghost tracks, we now have six duplicate notes. Each Ghost track can now be transposed to create the desired harmonic intervals, as shown in this example.

These six notes, which make up an A Major chord, are now automatically output from the Ghost tracks each time the note A1 is played from the master track. In fact, the Ghost tracks can be triggered from any note to give a Major chord, the key of which is determined by the note played — for example, F1 will yield an F Major chord.

The problem now is how to play this trigger note in rapid succession. We need to create a second trigger note to play another A Major chord. Firstly, we must isolate the Ghost tracks already created, so that their operation is note‑specific (in other words, so that they will only copy one specific note on the keyboard). This is done by setting Highest and Lowest note ranges (available in the Track Parameter box) of each of the Ghost tracks to the intended trigger note (in the above example, the highest and lowest note ranges would both be set to A1). See Figure 5.

From the ten remaining tracks within our working pattern, we can create a further six Ghost tracks, but this time, we will set the highest and lowest note ranges to any note other than A1 — say for example A2. See Figure 6.

These six new Ghost tracks must also be transposed as before, but if we apply the same values as above, the resulting chord will be an octave too high, because the source note is one octave higher than before. We must therefore deduct 12 from each of the previous transpose values to achieve the same chord in the same octave, as shown in Figure 7.

This second chord of A Major is identical to the first, but this time is triggered only by the note A2. Now we have two identical, yet completely separate A Major chords, which can be played in rapid succession via their respective trigger notes. We can further enhance the authenticity of these chords by introducing delays to each Ghost track, to simulate the minute timing differences between the pluck of each string as a guitar is strummed. For example, when a guitar is strummed in a downward motion, the 6th string is plucked first, and the 1st string last. So, using the Delay feature available in the Track Parameter box, the following example settings can be introduced to our Ghost tracks, as shown in Figure 8.

We now have an A Major chord which is triggered whenever the note A1 is recorded by the master track, and is played in a simulated downward motion. Similarly, these same delay values can be applied to the remaining Ghost tracks in our pattern to achieve an A Major chord strummed in an upward motion. In order to realise this, the delay values should be applied the other way around, so that this time Track 7 (A1) is played last (and therefore delayed by 13 pulses), whereas Track 12 (A3) is played first (and is subject to no delay). In a similar way, velocities of each Ghost track can be adjusted to taste, to emphasise the lower or higher strings of a chord. It is important to note that any delay values can only be monitored whilst in the play or record mode, since they are clock related. Also, the amount of delay or velocity change introduced can vary a great deal, depending on the tempo of the song and the desired strumming style. All the parameters needed to create an A Major Ghost pattern can be summarized as shown in Figure 9 overleaf (try entering the values into a pattern yourself);

Having created our Chord Pattern, we can now record any number of bars of guitar strums in track 16, simply by playing the pre‑defined trigger notes (in this example, A1 and A2), or by recording just one or two bars of strumming, and looping them. Numerous patterns can be created for a whole range of chords (Majors, Minors, 7ths, etc; see Figure 10 below for different transpose values).

These patterns can be entered into an existing song arrangement wherever their specified chord is required. Where a short sequence has been entered into the master track and looped, the length of this pattern is unlimited and therefore all such patterns must be entered in just one arrange bank, because the length of each pattern can only be determined by the start position of the next pattern in the arrange bank. See Figure 11, left.

This is a quick and easy method of pasting the same pattern anywhere in the song arrangement. Indeed, the same pattern could be used in any key, simply by entering the desired key change value in the Transpose Pattern box (in the bottom left corner of the main page). Slight glitches are sometimes audible, where notes sustained from a previous pattern are cut short by the beginning of the next pattern in the arrangement — this is because Creator and Notator automatically insert the necessary note‑offs at the beginning of the next pattern to avoid droning notes. Care needs to be taken when recording the master track, to ensure that notes are not sustained any longer than is necessary.

Having arranged the patterns throughout the song and completed the guitar track, we need to convert all these patterns and Ghost tracks to real events, so that we end up with one complete guitar track. This is done by following the simple steps below:

1. Excluding the ghost tracks, mute all other tracks, including all the master tracks.

2. Set Midi Click ( found in the MIDI pull‑down menu), to off (unticked). See Figure 12, below.

3. From the same menu, set Midi Thru to Off. See Figure 13, below.

4. From the Input Handling box, again found in the MIDI pull‑down menu, filter out all control, channel pressure, and pitch bend data, by clicking on the relevant boxes (grey letters on a white background means filtered out). See Figure 14, overleaf.

5. Perform Overlap Correction (found in the Functions menu) on all master tracks, to ensure that no notes overlap, as any such overlap would be multiplied twelve times, using up polyphony on your keyboard or sound module.

6. Using a standard MIDI cable, connect the MIDI Out port to the MIDI In port on your Atari. See 'MIDI cables' box elsewhere in this article.

7. Select any empty track (provided it runs for the whole length of the song), and set its quantize value to 768. Ensure that it is set to the correct MIDI channel, then enter record mode.

Conversion is now completed in one simple pass of the song, and whilst it cannot be monitored, due to the temporary lack of the MIDI Out port, conversion can be seen to be taking place by watching the free event counter at the top left‑hand corner of the main page.

Once conversion is completed, all that remains to be done is a simple reversal of steps 1‑4 and 6, and your guitar track is completed. All Ghost tracks and master tracks can then be deleted.

The possibilities using this Ghost feature are endless. For the more curious readers, the 'Pointers' side panel provides some more ideas for you to explore.

MIDI Cables

Make sure, when connecting your MIDI Out port to your MIDI In, that you are using a proper MIDI cable, i.e. one which has only the three middle pins wired (pins 2, 4, and 5). It is advisable to actually pull off the insulating cover of one of the cable connectors to visually confirm this, as even some cables marked 'MIDI Cable' are in fact just ordinary 5‑pin DIN cables.

Pin diagram of a MIDI cable — external view. Pins 1 and 3 must be disconnected, whilst Pins 2, 4, and 5 are connected.

Alternatively, use an ordinary 5‑pin DIN cable, but disconnect pins 1 and 3, and cut off the two unwanted wires at the point where they emerge from the outer insulating cover, in order to avoid any short‑circuiting. It is only necessary to do this at one end of the cable.

Care With Cables

One important note is to take care when repeatedly plugging and unplugging MIDI cables from the Atari MIDI ports, as these are easily damaged with overuse. One practical solution is to fit small extension cables to the ends of your existing cables, to provide access points at which you can then patch your Atari In to Atari Out using the appropriate adaptor.


  • Try making up your own Ghost patterns, using the transpose values found in the Example Settings panel. As for velocity and delay, try experimenting with your own values. Remember: the larger the delay value, the longer or slower the chord strum.
  • The Highest/Lowest note ranges for a pattern of Ghost tracks need not necessarily be limited to just one note. For instance, the two Ghost chords set up in the above example could have been limited to a specified note range, (say E1 to D#2, and E2 to D#3), rather than each being limited to one trigger note (A1 and A2). This would have provided a range of Major chords.
  • Different Ghost patterns could be allocated different note ranges. For example, a pattern set up to play Minor chords could be given the note ranges E3 to D#4 and E4 to D#5, whilst another pattern set to play, say, a Minor 7th, could be given the note ranges E5 to D#6, and E6 to D#7. In this way, three different patterns, playing three different chord types in any key, can be accessed simultaneously, simply by running them in parallel in the song arrangement (i.e. one in Bank B, one in Bank C, and one in Bank D).
  • Using our A Major pattern as an example, suppose we shifted the note ranges up by, say, four octaves, to A5 and A6. The result would be an A Major chord pitched 4 octaves too high. Instead of adjusting the transpose value of each individual Ghost track in the pattern, we can simply transpose the whole pattern down to the desired pitch, using the Transpose Pattern function found on the main page.

Guitar Aid

Sean Kenny has collated over 1000 template patterns covering every chord in every key. This is for sale, along with an easy‑to‑read and heavily illustrated manual that explains the recording procedures in full. The manual also includes chord charts showing many of the chords covered by the template patterns. The collection is called Guitar Aid and is available on disk for £14.95 from: Sean Kenny, PO Box 408, Maidstone, Kent ME15 8XX. Cheques should be made payable to Sean Kenny.