Avoiding Portamenti

[joaz]

I wondered what is the best way of avoiding Potamenti(Shifts), when you want a smooth legato.
The passage I am working on, has low expression values (cc#11), and I want low velocity values whenever possible.
Sometimes to avoid portamento, I have to go from a velocity of 20 to a velocity of 85/90, but this does not sound very smooth.
Also does the velocity-off have any bearing on the outcome.?
I love the portamento effect on this instrument, it is very lifelike, but I wish I could have a little more control over it's use.
regards

[Giorgio Tommasini]

Joaz,

The Stradivari Violin has been programmed to yield portamento/legato on note overlaps. The portamento rate is dependent both on overlapped note-on velocity and note intervals. The velocity/portamento rate function approximates a modified hyperbola, in that it becomes flat at velocities around 90-100. At these velocities, no portamento occurs, and pure legato takes over. Conversely, the steep portion of the hyperbola allows for a very wide range of portamento rate on low velocities.

Please note that on note overlaps, note-on velocity exclusively affects the portamento rate. It has no effect on the dynamics, timbre etc.
Hence, there is no need of using low velocities if pure legato is what is needed.

Giorgio

[joaz]

.
Hence, there is no need of using low velocities if pure legato is what is needed.

Giorgio

Thank you Giorgio, all is now clear.The problem was the passage lacked overlapping notes.
With this help, I can now control the portamento perfectly. And I admire the programming, because you can have a very small portamento, or a huge romantic swoop.
regards

[ZeroZero]

I am trying to understand the difference between portamento and legato. Isn't it the same thing? I (think) I understand that portamento is usually used to describe larger slurs between notes of larger pitch difference?
I dont know what this sentence means:

"The velocity/portamento rate function approximates a modified hyperbola, in that it becomes flat at velocities around 90-100."

What is a modified hyperbola?

Any help please

Zero

[Giorgio Tommasini]

Zero,

There is indeed a substantial difference between portamento and legato, both in real life, and in the way these transitions have been implemented in the Stradivari.

This is however reserved information, and I very much regret not to be able to disclose it.

By a modified hyperbola I meant the sum of several functions, leading to a non-asymptotic, nearly horizontal segment, for note-on velocities in the range 90-127. This essentially means that the duration of the legato transition will be affected only slightly by velocities above 90.

Giorgio

[Tovan]

How do we know when two notes are overlapping instead of it being polyphonic? In the music I have, note durations do notcross eachother but there is minor chords being played ... all note velocities are at 100 and still portamenti occures ...

[ZeroZero]

Dear Giorgio,
"By a modified hyperbola I meant the sum of several functions, leading to a non-asymptotic, nearly horizontal segment, for note-on velocities in the range 90-127. "

Duuhhh!!! and I am a maths teacher!

I do understand that in real playing there is a world of difference between a portamento and legato, but in Virtual world surely both are the morphing between two tones?

Liked your answer though it got my other brain cell functioning.

[joaz]

I am trying to understand the difference between portamento and legato. Isn't it the same thing?
Any help please

Zero

Imagine a violin playing a C rising to an F (8ve above middle C, played on the A string)
The violinist puts his 1st finger down , smoothly draws the bow, then puts his little finger down. That is Legato.

The violinist puts his 1st finger down , smoothly draws the bow, then slides the first finger up to an F. that is Portamento. Sometimes called a shift or slide.

2 different effects. 2 different sounds.

hope that helps.
regards Joe

[Tovan]

um... I trimmed the durations of the notes, seperating them even just by 1 unit, and I looked through the event lists in Fabio's Midi Version of the Bach Sonata ... It looked ... very very very very very ... complicated.

I just tested several things ... sigh, even with the trimming the skipping still occures tho the port is diminishing.

[ZeroZero]

Joaz Yes that helped, I can understand the difference now in real violins.