The Motif XS/XF, MOX6/MOX8, S90XS/S70XS, and MOXF6/MOXF8 add Expanded Articulation (XA) to their list of voice technologies.
Exactly what is this?
Those who can remember the first time you heard a Yamaha Tyros 2 may recall it introduced an amazing range of ancillary instrumental behaviors (slides, pops, noises, etc.) that made them a world apart from mere synthesized or sampled sounds. The current synths take some of this type of raw material and places it in the hands of you, the user. While the Tyros introduced this kind of articulation, it is primarily used by the STYLE engine to increase the realism of guitar and bass accompaniments. The “XA CONTROL” parameter puts this under your fingers so that you can articulate the phrases by how you touch the keys.
For example, the main piano “Full Concert Grand” is an 8 Element Voice. An ELEMENT is a multi-sample component of the Voice. Each Element can contribute a part of an instrument sound or the entire instrument sound. In the case of the Full Concert Grand piano, Yamaha meticulously sampled a CFIIIS Concert Grand at three different velocity levels. Why? Because the piano, as an instrument, speaks differently when played pianissimo versus when played mezzo-forte, and still differently when struck fortissimo. The harmonic content changes. As musicians you should know that harmonics are the whole integer multiples of the fundamental pitch… and are what the ear/brain use to identify sounds. Harmonics are like the fingerprint of the sound. Each sound has a unique configuration, in terms of the loudness of its upper harmonics.
You recognize your friend’s voice by its harmonic content. You recognize the difference between a trumpet playing “A440” from a trombone playing “A440” because, even though they are playing the same pitch, the harmonic content of the two instruments is different. As you hammer, strike, pluck, blow or bow any acoustic instrument with more vigor, the richer the sound is in harmonic content. And the relationship in relative loudness of the harmonics change as there is an increase in intensity.
Think of striking a crash cymbal with a stick. Strike it softly. Now, strike it hard. A lot more changes than just the volume. You can easily tell, no matter how loud the volume it is played back, whether that cymbal was struck lightly or with great energy...turning the volume down on a hard struck cymbal does not hide the fact that it sounds like it was really smashed. The same is true of the subtlties of the piano - which is also a “percussion” instrument. You can tell whether a note was originally played softly or struck hard - and this is why a triple strike piano is important… it is a kind of articulation. We’ll define “articulaton” as a gesture that evokes a particular music response from an instrument. When you play a quiet passage on the Full Concert Grand you will “feel” the difference versus when you are really digging in. And the cummulative result is that soft passages will speak with a different tonality than a more vigorous performance. This is important for how musical phrases sound, overall.
This piano is constructed from a triple-strike sample waveform set that is mapped for four-way velocity response from the low and mid-ranges of the of the piano (through to G5) and is a three-way velocity layer above G#5 (where the acoustic piano has no string dampers). So as you increase your playing intensity you are switching between different sample sets, and the programs touch response curves.
The XA Control parameter can be assigned to the 8th Element which articulates the Key-Off Sound for the main body of the sound. Key-Off Sound on a piano creates the sound of the hammers and dampers returning to mute the vibrating strings. So although the piano is an 8 Element Voice, it only ever uses a maximum of two Elements simultaneously for any one note-on event.
XA Control can also be assigned to things like legato playing. This allows the programmer to specify an Element or Elements to be sounded only when playing legato. Rather than retriggering the Element that is responsible for the attack, certain of the Elements can be placed under XA Control for “Legato” and the Legato Element will only sound when you have articulated a legato phrase. The attack Element, if you will, will not sound during the legato articulation… that is, you control the attack by releasing and retriggering the sound, if you connect the notes the envelopes don’t retrigger. This is as stunning on acoustic instruments as it is on synth leads and synth basses.
Combining this “Legato” articulation with the “Key-Off Sound” on a lead instrument like a reed instrument, for example, means you can have Legato playing for solo lines and you can have the key pad sound articulated when you let go of a note (Key-Off Sound could be the key pad of the horn returning to cover the hole). Key-Off sound could be used to great effect, and is, on guitar plucks, harpsichord quills, Clavinets, etc. and Legato for hammer-ons, etc.
XA Control can be used in precise ways to control what the keyboard is doing - and this is up to you as a performer. You can assign the XA Control per Element and can determine if an Element will sound only under certain circumstances. Say on a lush string orchestra sound you need to articulate a prominent bow stroke, you can assign certain of your 8 Elements to groups, these groups can be recalled when you activate a specific controller (there are two new buttons on the front panel [AF1], and [AF2]). The Assignable Function buttons can help you articulate the change or you can assign the function to a foot switch or whatever controller helps you ‘perform’ the sound). And, of course, the controller manipulations can be recorded to the sequencer.
Big bowed orchestra to pizzicato; slow bows to quick strokes; single to ensemble; Sforzando-build to fall-offs, small room to grand canyon, etc. You can determine the articulations that you need.
Some of the new woodwind legato voices switch between 3 velocity layers of waves with attack and sustain legato waves. They also have key-off samples. However, even though they use 7 elements there is never more than 1 element playing at any given time! What that means is even though the Voice has 7 Elements it is not expensive in terms of the polyphony that it uses.
Expanded Articulation is not limited to natural/orchestral instruments. It can also be used to create Wave Cycles or Wave Random articulations where each key strike goes through a predetermined change of Element or can randomly order the Elements. The results here can be stunning and very useful in electronic and synth sounds adding a different dimension to your music.
Expanded Articulation not only adds another level of sound to your Voices, it does so intelligently and interactively.