Arpeggiator Tips

A simple Environment setup for using an Arpeggiator Object.

In the first of our new regular software columns based on the leading sequencer packages, Paul White gets Logic Notes off to a flying start with some invaluable hints and tips.

Most people who are into electronic music like to dabble with arpeggiators, yet when I ask fellow Logic users what they think of Logic's arpeggiator feature, the usual reply is that they haven't got around to trying it yet. Perhaps the real reason is that the arpeggiator is an Environment Object, and more people than would care to admit it tend to stay away from Logic's Environment once they've finished configuring it for their system. However, setting up the arpeggiator is a doddle and some of the effects that can be obtained can't be duplicated using less sophisticated arpeggiators. What's more, you can set up as many arpeggiators as you like, each on its own track and controlling its own synth, sampler or drum patch. And if you're really into sonic 'knitting', you can cable together a number of arpeggiators, delay lines and other fun Environment Objects so that even a simple chord produces a hugely complex result that rambles on for several bars. I have to admit that I'm hooked on it, so if you think you'd like to give it a go as well, read on and I'll go through the basic setting up.

Stairway To Arpeggiation

A chord, shown in the upper editor window, has been arpeggiated according to the parameters shown at the bottom left. The resulting arpeggiation has been recorded onto another track and it is shown in the lower editor window.

Step one is to open the Environment layer where your Instruments reside and to create an Arpeggiator Object from the New menu. At once a little icon showing notes on a musical stave appears in your Environment, and when you go back to the Arrange window, it's this Arpeggiator Object that you select as the track Instrument. So far so good, but as yet the arpeggiator isn't controlling anything. For that, we need a cable (virtual cable), and that means staying in the Environment for a while longer. If the synth to be controlled is a Standard Instrument, then all you need do is drag the cable from the Arpeggiator Object's output to the Instrument you wish to control and you're ready to start playing. However, if you want to play one part of a multitimbral instrument, represented in the Environment by a Multi Instrument Object, the manual is less than clear about how to achieve this. Fortunately, there are at least two ways to do the job, both of them simple.

The first method is one I came up with out of frustration at not being able to find an official way. I simply created a new Standard Instrument with the same channel and port settings as the part I wanted to access, then ran a cable from the Arpeggiator Object to my new Standard Instrument. It worked fine, and if you bring up the original Multi Instrument in a spare track in the arrange window, you can use it to change patches for the part being arpeggiated. Figure 1 shows Logic's Environment with an Arpeggiator feeding a Standard Instrument that duplicates one of the parts of my Roland JV2080's Multi Instrument.

The second method, passed on to me by Ian Cullen of Sound Technology (Emagic's UK distributors), involves holding down the Alt key (Mac) or Control (PC), then selecting the output cable of the Arpeggiator Object in the Environment window. This brings down a list of all the active Instruments available in Environment, and you simply scroll down the list to the one you want before releasing the modifier key. This also works fine, but if you forget what part of the Multi Instrument is being controlled, you can't tell from the cabling, as the virtual cable just disappears into the top of its icon. Once again, the actual part being controlled can be brought up on a spare track to allow you access to its patch list or other part parameters.

Boxing Clever

Once you've configured your Arpeggiator Object, you're ready to try it out, but don't make the mistake of playing your keyboard and wondering why the sound isn't being arpeggiated — the arpeggiator is linked to the tempo clock of the song, so unless the sequencer is in play or record you'll hear only your selected patch as normal, without any arpeggiation.

You'll notice that when you select the track with the Arpeggiator in it, the parameter box to the left of the screen changes to a special version relating specifically to the arpeggiator. By changing these parameters, you can affect the way the arpeggiator behaves — this is the key to the versatility of this little virtual device. If I may proffer a tip at this point, it helps to assign different colours to your Arpeggiator Objects (View menu/Object Colours) if you have more than one set up, as it prevents you selecting the wrong one by accident.

The first arpeggiator parameter is Direction, which may be set to Up, Down, UpDn (up and down), Auto, UpD2 (a variation on UpDn), Random or All. The latter repeats all the notes as chords. Auto is one of the most musical options as the direction depends on the order in which the notes were played. The Velocity setting can fix velocities to a value of your choosing, can leave velocities as those that were originally played, or can randomise them. These settings affect only the velocity values of the notes feeding the arpeggiator, which leaves scope for further velocity processing within the arpeggiator.

The Lim parameter used to catch me out because it defines the note range over which arpeggiation will occur. If a note is played outside these limits, it plays normally with no arpeggiation. The default is G2 to C6, so tweak accordingly if you wish to get really creative with registers. Res sets how quickly the individual arpeggiated notes are produced, while Length defines the duration of each of these notes.

Snap To allows you to set a timing grid to which input notes are forced before being passed to the arpeggiator, such that the arpeggiator begins to produce notes often only after the input note is played. The manual suggests that, for normal‑sounding arpeggios, this be set to '1/4' for 4/4 time‑signatures, though it can also be turned off — if recorded notes are already quantised, Snap To is just as well left off.

The Repeat function can be on or off. When on, the arpeggio continues for as long as the chord is played, whereas selecting off means the arpeggio sequence is played only once. Octave sets the number of octaves over which each incoming note is arpeggiated, and this may be set from one to 10 octaves. Obviously anything arpeggiated out of the note range of the instrument being controlled won't play. Crescendo is one of those fun settings — here you can set a velocity to be added to or subtracted from the arpeggiated note each time it comes around. This way you can have a held chord whose arpeggiation automatically increases or decreases in level as it progresses.

An advanced feature of Logic's Arpeggiator is that each of the parameters in its parameter box can be controlled in real time using MIDI controllers. The Ctrl Base parameter allows you to pick the controller that will be used to set the arpeggio direction (the first parameter). Successive parameters then respond to successive controller numbers. I have to admit that I've never had any reason to explore the possibilities of this option, but it's nice to know it's there if you need it.

Right Round, Baby, Right Round...

As you can see, setting up and using the arpeggiator function within Logic is not difficult, but there are a couple of points to bear in mind. Firstly, there's the one I mentioned earlier — the arpeggio won't happen unless the sequencer is running in play or record. Secondly, all those magical extra notes come from your synth, not from a delay line or a pitch‑shifter, so they use up real polyphony. Another point to remember is that no matter how many octaves you dial in, the arpeggio range is limited by the synth responsible for generating the sounds. Other than that, there's little that can go wrong and you can have a lot of fun, even if you're not into conventional electronica.