"Quantize" to varying tempo?

Archived from groups: rec.audio.pro (More info?)

Scenario:

You have recorded a song with many audio tracks using a DAW, and you
like the results. The tempo, however, varies throughout the song
(verse, chorus, etc), and at times is unsteady. Still, you like the
results.

What you would also like to do is add a midi part or two (maybe some
synth strings, or percussion).

Aside from manually altering the position of each note, is there a way
to “quantize” the midi parts to your audio track to match the ebbs and
flows of the tempo?

--
Ratt Mahem
www.themourningsickness.com

Archived from groups: rec.audio.pro (More info?)

Ratt Mahem wrote:
> Scenario:
>
> You have recorded a song with many audio tracks using a DAW, and you
> like the results. The tempo, however, varies throughout the song
> (verse, chorus, etc), and at times is unsteady. Still, you like the
> results.
>
> What you would also like to do is add a midi part or two (maybe some
> synth strings, or percussion).
>
> Aside from manually altering the position of each note, is there a
way
> to "quantize" the midi parts to your audio track to match the
ebbs and
> flows of the tempo?

You can laboriously create a tempo map that matches the ebbs & flows of
the original performance and then automatically quantize any MIDI info
you play in. OR, you could just perform the parts and fix whatever
little bits need fixing by moving the MIDI notes manually. For synth
string stuff, a decent player should be able to play the parts with no
need for any quantizing at all. The percussion may be a bit more
complicated, though again if you can play it well, it shouldn't need to
be corrected much.

Andrew

Archived from groups: rec.audio.pro (More info?)

>You have recorded a song with many audio tracks using a DAW, and you
>like the results. The tempo, however, varies throughout the song
>(verse, chorus, etc), and at times is unsteady. Still, you like the
>results.
>
>What you would also like to do is add a midi part or two (maybe some
>synth strings, or percussion).
>
>Aside from manually altering the position of each note, is there a way
>to “quantize” the midi parts to your audio track to match the ebbs and
>flows of the tempo?

The better sequencer programs have a tempo map function. The one in
Cubase SX3 is particularly easy to use.

But why quantise? Play in the midi parts the same way the original
instruments were recorded - freely, using your ears to get notes in
the right place.

CubaseFAQ www.laurencepayne.co.uk/CubaseFAQ.htm
"Possibly the world's least impressive web site": George Perfect

Archived from groups: rec.audio.pro (More info?)

Ratt Mahem wrote:

>Scenario:
>
>You have recorded a song with many audio tracks using a DAW, and you
>like the results. The tempo, however, varies throughout the song
>(verse, chorus, etc), and at times is unsteady. Still, you like the
>results.
>
>What you would also like to do is add a midi part or two (maybe some
>synth strings, or percussion).
>
>Aside from manually altering the position of each note, is there a way
>to “quantize” the midi parts to your audio track to match the ebbs and
>flows of the tempo?

Cakewalk (and Sonar, presumably) has a feature called "fit improvisation."
You overdub a quarter note track to the improvised take and it uses that
track to figure out what happened tempo wise and to adjust event times
and add tempo changes to produce measure alignment.

But I agree with the others who say in that there may be no need for this
in your scenario, and you can just record the MIDI parts in "free form."
Yes, the measures won't align, but unless you will need to process those
MIDI parts in ways that require measure aliignment, you don't have to
care. And really, if the MIDI parts need the processing then you should
hire a better performer. I don't mind removing a "fat finger" now and
then, but needing to adjust the timing of more than a couple of notes
indivates that I don't yet have an acceptable take.

When I do this sort of thing I set the MIDI sequencer's tempo for 240
BPM with a time signiture of 4/4. This makes for a handy measure duration
of one second.

--
========================================================================
Michael Kesti | "And like, one and one don't make
| two, one and one make one."
mkesti@gv.net | - The Who, Bargain

Archived from groups: rec.audio.pro (More info?)

Logic Audio 5.0 enables you to convert audio to MIDI. So, you could
take a rhythmic audio track and convert it to MIDI, thereby giving you
an exact MIDI copy of the rhythm fo the whole track . . . it might not
get the notes right from the audio 9unless it was simple, monophonic
audio), but you don't need them, only the time-position as MIDI.

Then you could play the new MIDI tracks, and then any make any
adjustments as necessary by moving the new MIDI notes to the same
time-point as the MIDI-from-rhythm-track. A bit laborious, but this
would give you exact "quantisation" to the rhythm track as played live,
and MUCH quicker and more effective than guessing which way to move the
MIDI notes to get it to fit the audio.

If you wanted to get into even more detail, you could use this method
to get a VERY exact tempo-map of the audio . . . changing the tempo
each bar if necessary, which is fairly easy once you've got an exact
MIDI template, as you can cut the audio exactly on the MIDI notes.

Chris
www.chris-melchior.com/strings.htm (REAL strings for realistic prices)

Archived from groups: rec.audio.pro (More info?)

Laurence Payne wrote:

> Think it through. A frequent reason for wanting midi bar and beat
> alignment is to apply a quantised drum part. Such a part will sound
> very odd if you apply a constantly fluctuating tempo map.
>

I use it the other way around: to add keyboards to an existing track;
the tempo frequently goes all over the place , with a tempo event per bar.
The funny thing is that looking at the tempo changes you'd think it'd be
rubbish, but it's actually pretty tight, and certainly not as sterile as
a quartz-controlled tempo. And being able to move/copy a keyboard part
to somewhere else in the song without any tweaking is fantastic (like "
hey, let's try how that piano fill fits in the first chorus instead of
the second ".

I think with most great bands tempo is a living thing and certainly not
steady in a way that a computer is


Hans
--




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we didn't plan it that way, but it is

=====================================


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Archived from groups: rec.audio.pro (More info?)

ProTools aswell. Actually ACID has really easy to use tempo map tool,
much like Cubase's. What program are you using?

Another good thing about tempo maps is if you have a delay set to a
particular note-length (16th note for example) it helps to keep that in
time as well.

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chris@chris-melchior.com wrote:
> Logic Audio 5.0 enables you to convert audio to MIDI. So, you could
> take a rhythmic audio track and convert it to MIDI, thereby giving you
> an exact MIDI copy of the rhythm fo the whole track . . . it might not
> get the notes right from the audio 9unless it was simple, monophonic
> audio), but you don't need them, only the time-position as MIDI.
>
> Then you could play the new MIDI tracks, and then any make any
> adjustments as necessary by moving the new MIDI notes to the same
> time-point as the MIDI-from-rhythm-track. A bit laborious, but this
> would give you exact "quantisation" to the rhythm track as played live,
> and MUCH quicker and more effective than guessing which way to move the
> MIDI notes to get it to fit the audio.
>
> If you wanted to get into even more detail, you could use this method
> to get a VERY exact tempo-map of the audio . . . changing the tempo
> each bar if necessary, which is fairly easy once you've got an exact
> MIDI template, as you can cut the audio exactly on the MIDI notes.
>
> Chris
> www.chris-melchior.com/strings.htm (REAL strings for realistic prices)
>

Thanks Chris... this really helps.


Matt.

--
Ratt Mahem
www.themourningsickness.com

Archived from groups: rec.audio.pro (More info?)

Ratt Mahem wrote:
> Michael:
>
> Will it work with an existing audio track? Is it for the Mac?
>
>
> Matt.
>
> --
> Ratt Mahem
> www.themourningsickness.com

Matt -

InTime runs on both OS X and Windows. It doesn't work on existing audio
files. It's a live-feedback tool, so you generally use it while
recording a track. It can work on recorded tracks, but it depends on
how much variation there is in the track.

It currently can follow any MIDI-capable instrument, and works great
with acoustic drum kits setup with MIDI triggers, or by using
audio-to-midi software to convert audio into midi before sending it
into InTime. For some details about using InTime with drums:
http://www.circular-logic.com/Drummer_setup_tips.html

We're working on an audio version that will take live audio input
directly, but working universally on existing recorded audio is still a
ways off.

Cheers,
Michael