I believe what you're referring to, in having the tempo sync to an external audio source, is "audio beat sync".

https://www.youtube.com/watch?v=IRlgglsj7i0

https://www.youtube.com/watch?v=ehIYqP7Ti64

https://www.youtube.com/watch?v=_UK5YiCLr44
(turn on CC and auto translate for your locale)

https://www.youtube.com/watch?v=ryjCucgYjYA
https://www.youtube.com/watch?v=LmpiGVmlhJg (part 1 for good measure)

BTW: The "Mastering Montage" series has received a facelift, updating for the newer firmware. Which is great - but it broke all the old links that are still hanging around here. Go here for the latest "Mastering Montage" series roundup: https://yamahasynth.com/synths/montage-article-roundup-os-v3

That page would be great if the links worked - but they're mostly goofed with 404 errors. And this must have been done recently since google hasn't caught up and indexed the new pages yet.

Here's the new page to the envelope follower article: https://yamahasynth.com/synths/mastering-montage-envelope-follower-video

This isn't going to help you with audio beat sync however. It's for modulating a sound inside Montage with an external sound (creating an envelope and that output modulates a parameter).

Note you can still find all of the articles if you search in google for the title, use google's cache to read the cached version - and you can pick out an exact phrase unique to the article and search for that in this forum (use "exact phrase" ). This will bring you to the new link.

Here's a forum thread on audio beat sync:

https://yamahasynth.com/ask-a-question/montage-envelope-follower-audio-beat-sync

Thanks for the reply. I found the first two videos before posting last night. The first one showed me that I can some of what I wanted. The second I couldn't do the reading and haven't spoken French since High School over 35 years ago. When it's late at night - about the only time I have to research, I like to listen to videos, rather than read. I almost stated ABS instead of Envelope Follower because some guy was ranting about it in the comment section of one of those videos...

Anyway, I'm wondering if I can send out from either the main or aux outs into the A/D input to have the Montage control itself that way...and if so, will it trigger a pattern that follows me while I play lead?

Thanks again.

If you're playing a drum part and send the bass drum (4-on-the-floor pattern) out AUX then back into Montage's A/D input then the tempo should be able to fairly easily follow that. If you're going to be sending your piano out - the beat sync is going to have a hard time figuring out where the beat is.

Say you're just sending the A/D input your lead line. You have a 16th note run pickups - 4 quarter notes (1 measure) - then hold two tied whole notes for the next two measures. How can tempo be resolved with this data? Fairly difficult to feel the pulse of held notes.

It doesn't take much time/effort to experiment. Try it. Have low expectations for a robot to recognize tempo. Best to "baby" the robot and feed it something easier to follow.

If using the A/D can control the playback tempo of the Montage (ie through a drummer), can you have a Pattern or Song on the Montage follow your live playing?

No. The design (like most gear) focuses on you following it, not it following you. Auto Beat Sync is a foray into this ‘twilight zone‘ of tempo interactivity

In other words, can I create a backing track and have it trigger when I start playing and follow my tempo as I play?

You can have a Pattern trigger when you touch the Keys but it will follow the tempo as set currently — that is, the Tempo will follow its own built-in clock time (Internal), or via an external tempo via MIDI, or via the A/D In.

A Pattern can be set to “Key On Start“ so that touching a key starts playback, but generally you play your lead along to the tempo set for the Performance/Sequence..

You, playing lead, actually don’t provide enough information, rhythmically, for the technology to follow you.

Say by using Envelope Follower can it sense the tempo from my left hand and follow what I'm playing live?

The synth does not have ears and does not listen to you. It derives tempo from regular input. MIDI Clock delivers a steady stream of pulses that work like a gear system in a watch or clock, they interlock and move the musical time forward.

The Envelope Follower can detect every note you play and you can use this as a modulation source elsewhere in the Motion Control engine — but it is not necessarily a selectable source for tempo input. And because it would work similarly (pulse amplitude) even if you could feed it to a Tempo control input it would not be able to effectively interpret tempo of something like a lead line.

Interpreting a “lead line” would require it to listen to what you are playing and make an esthetic decision about what to do — that’s what you generally pay a drummer to do, but they mostly aren’t listening to your every note either!!! Even when you pay them.

In actual use the lead player follows the tempo of the band (not the other way around). The lead player can visually speed up the band, but even playing faster does not immediately make a band play faster, mostly they are trying to remain at the original tempo. These vary from song to song... and band to band, for that matter.

Of course, as broad a subject as MUSIC... you might want a situation where you can manually control the MONTAGE tempo — that is currently handled by the Auto Beat Sync function and Tap Tempo, which can recognized incoming pulses from which it can derive Tempo.

Tap Tempo can be used to manually control the tempo change... both of these work on an amplitude (gain) spike and an analysis of the spacing between pulses (spikes). Tap Tempo requires three hits to derive an average spacing between the hits and thus creates a Tempo Change based on the timing placement of the pulses. They must be fairly regular — an esthetic pause in your phrasing would/could be disastrous to the tempo. (Mainly used for tempo change...once you give it input the tempo persists).

ABS begins to move toward the ability to ‘listen’, as it has some built in intelligence that can sort between strong low frequency hits and higher pitched snare and Hihat hits, so you can see it doesn’t always get fooled when the pulses change from kick to snare. It seems to be able to recognize the difference in the standard drum hit vocabulary (but like your drummer it is not literally listening to you and making musical decisions about what to do when you play a particular phrase or lick.

Both ABS and Tap Tempo are dependent on a fairly steady source to set the tempo.
Envelope Follower as an interpreter of Individual lead events would be fine, but it requires constant input — its use as a modulation source requires input... Silence is interpreted as a STOP command. Imagine a watch that was only able to move forward when you yourself were moving. You would quickly lose faith in it for its designed purpose... you want it to ‘know‘ to continue counting without you telling it to count.

Practice using Tap Tempo — this is real time control over Tempo input. Best case scenario you would need to tap the tempo (audibly) while also playing your lead... so that your tempo would continue (remain at last setting) even when you are holding a note.