With the caveat that the term "shake" is even more abstruse and little understood here in the sound isolation studio than "trill", as best as I can determine this particular articulation in NOTION 4 (64-bit) depends strongly on the particular instrument and the way the particular instrument is programmed with respect to having the relevant sampled sounds and to being able to play the relevant sampled sounds correctly based on the MIDI commands and instructions NOTION 4 sends . . .
This is the way wikipedia defines "trill" and "shake":
The trill (or shake, as it was known from the 16th until the 19th century) is a musical ornament consisting of a rapid alternation between two adjacent notes, usually a semitone or tone apart, which can be identified with the context of the trill.
[SOURCE:
http://en.wikipedia.org/wiki/Trill_%28music%29 ]
As I recall, the software designers and engineers at Notion Music use a specific reference as the source document for music notation definitions and rules, but at the moment I do not recall what this source document might be, although it is a recognized standard reference, and I think it makes sense to have one master source document for stuff like this . . .
Nevertheless, the way a trill or shake is defined in wikipedia does not map to the long version of what you are calling a "shake", because instead of the notes alternating by large intervals, the way I read the wikipedia definition indicates that each of the two notes in a "shake pair" individually will alternate by a semitone or whole tone, such that a "shake pair" of {C5, E5} will play in some variation of {C5, C#5, C5, C#5, C5, B4, E5, F5, E5, F5, E5, D#5} if the shakes begin on the original note but end in a turn . . .
As an experiment, I tried several instruments, including the NOTION 4 bundled Violin, but none of them did much of anything, including tremolo, vibrato, and so forth, but since I have Kontakt 5 (Native Instruments) I tried the Kontakt 5 Solo Violin, and it actually does something based on the following music notation, as is heard in the accompanying WAVE audio file . . .
"NOTION 4 (64-bits) Kontakt 5 Solo Violin doing Shakes" (The Surf Whammys) -- WAV (3.8MB, 1411-kbps, approximately 22 seconds)However, this is different from the way a "tremolo" or "shake" is defined in the NOTION 4 User Guide:
FiNGERED TREMOLOS (SHAKES)
A tremolo between two alternating notes is a fingered tremolo or shake. From the standpoint of playback, you can create a major second, minor second, major third, minor third, or perfect fourth fingered tremolos. On a score, this has a unique symbol: two notes of the same time value has one to three lines between them (almost like beams, but not touching either note). The total measure count of the two notes is the count of one of them.
[SOURCE: NOTION 4 User Guide, Page 170 ]
And this is the way the same music notation plays when the instrument is the NOTION 4 (64-bit) bundled Violin:
"NOTION 4 (64-bits) Violin doing Shakes" (The Surf Whammys) -- WAV (3.7MB, 1411-kbps, approximately 22 seconds)If I switch to using explicit notes rather than the shake articulation, as shown in the following image and corresponding WAV audio file using the Kontakt 5 Solo Violin, then it does what the NOTION 4 User Manual suggests the shake articulation should do, and for reference doing it explicitly works the same with the NOTION 4 bundled Violin . . .
[
NOTE: This is only the first measure, but it is the pattern for the additional measures . . . ]
"NOTION 4 (64-bits) Kontakt 5 Solo Violin doing Explicit Shakes at 180-BPM" (The Surf Whammys) -- WAV (2.7MB, 1411-kbps, approximately 16 seconds)Another thing I noticed is that NOTION 4 changes the ending note of a shake pair, which to me appears to be a bit odd, but it makes sense when you consider that the trill or shake is based on the duration of the first note in the pair, hence the second note serves another purpose, and best wishes on guessing it might be . . .
THOUGHTSSince I am focused on practicality, all that matters to me here in the sound isolation studio is being able to find some way to do what I need to do, and it does not matter so much how long it takes or how much work is required. If the only way to do it is with explicit notes, then this works for me, and as an example it usually takes two or so hours to "sparkle" an instrument in a
DISCO or
Pop song that runs for three or so minutes, where "sparkling" is the name of the technique I developed for causing rapid sequences of ornamented notes to play in various patterns across the "rainbow panning arc" such that the notes move from far-left to top-center to far-right and then back and forth, which adds spatial motion to the notes played by the instrument . . .
"Sparkling" an instrument takes a while, but it is a stellar technique, and since NOTION 4 has true stereo panning controls, I can do it very precisely, where at the extreme I spread the individual notes for a single instrument over 8 staves, with each staff being panned to a different location. If the instrument is playing eighth notes and the tempo is 180-BPM, this maps to a lot of notes, and it takes a while to spread them over 8 staves, but I like the way it sounds, and there is no easier or more accurate way to do it, which is fine with me . . .
[
NOTE: This is an example of a "sparkled" Harpsichord, and it is done specifically for headphone listening. There are several patterns, where the first part has each note in a different location, but the last part has a phrase in each location at a slower pace. It finishes with alternating locations and then top-center . . . ]
"Sparkles" (The Surf Whammys) -- MP3 (4.3MB, 298-kbps [VBR], approximately 1 minute and 55 seconds)Based on my experiments, it appears that the NOTION 4 User Manual description of tremolo and shakes does not match what actually occurs, which makes it either (a) a problem or (b) something that I do not understand correctly . . .
Being able to do elaborate stuff via shortcuts and specially defined articulations can be useful, but as noted my focus is on being able to do it some way, and so long as I can do it at least one way, I am happy, which is fabulous . . .
Fabulous! 
P. S. As an odd but fascinating bonus, Elvis Presley does a uvular trill in "Hound Dog" on the "H" of "Hound" in the original recording, which is heard at 2:00 in the following YouTube music video, which is as mind-boggling as Scotty Moore's intro phrase to his second lead guitar solo (which took me about a week to discover how to play, and it is not easy, at all) . . .
Uvular Trill (wikipedia)[
NOTE: I have been studying this particular song for over half a century, and I only heard the uvular trill in an immediately conscious way sometime last year. It is easy to do uvular trills, but it is not something one intuitively thinks to do when singing, which is the mind-boggling aspect, since I doubt that Elvis had any idea what a uvular trill was at the time, which makes it an entirely intuitive instance of sheer genius. This is the original monaural version, and it is easy to hear when you listen with headphones at loud volume, which is the only way to listen to 1956 Elvis, other than with a calibrated full-range studio monitor system, where "full-range" refers to a flat equal loudness curve running from 20-Hz to 20,000-Hz at 85 dB SPL. And for reference, Elvis is doing syllabic singing, as contrasted to the melismatic singing style that James Brown uses in "Bewildered", which are my new musical theory concepts for the past week or so (melismatic and syllabic singing), really . . . ]
The Fabulous Affordable Studio Monitor System Project (IK Multimedia FORUM)"Hound Dog" (Elvis Presley) -- Syllabic with Vibrato, Uvular Trills, and Hiccups -- YouTube music video"Bewildered" (James Brown & The Famous Flames) -- Melismatic with Vibrato, Range Switches, and Textures -- YouTube music videoMind-boggling! 