Staff notation question: notating varying subdivisions

Ok here’s an issue that I run into all the time. I’m sure there’s a simple answer for this but it’s just not apparent to me because I’m dense. Let’s say I’ve got a picking pattern and I want to play it with a feel of threes and then change to a feel of four. I don’t want the picking speed to change, just the subdivision. How would you notate that?

A picture is worth a thousand words. Here’s some mandolin tablature:

The first four measures are triplets because the pattern fits that. I’m notating the fifth measure as sixteenths because the pattern fits a feel of four. In order to get Guitar Pro to play this thing back at what would be the same picking speed the whole time, I had to insert a tempo change to 75% of the original speed. You hit play, the notes all come out equal duration. But unless you’re a computer, there’s no way to know that’s what I’m intending.

There’s gotta be a simple way to notate to the performer that I want the note duration to remain constant no matter what the written subdivision is. Is this just a case where you’d simply write that in notes above the score?

Maybe you could have the first measures in 6/8, then move to 4/4? Dream theater would be proud :wink:

Edit: then all the notes become 16th notes. I guess the 6/8 16ths would feel a bit more like groups of 6 than 2x3

I’m not at a computer to test this in GP but are you sure this produces equal note duration? If you conduct 6/8 in a pulse of essentially 2, which is how it’s usually done (I think), then switching to 4/4 at the same numerical tempo would produce a pulse of 4 that is twice as fast. The sixteenth notes would end up faster than the preceding sextuplets. Am I getting that right?

Edit: I just tested this, and in Guitar Pro your solution works. Without changing the written tempo, the 6/8 sextuplets and the 4/4 sixteenths play back at the same speed. So that’s good!

I think what’s throwing me off is that to a human who is counting 6/8 time, the tempo reference is usually the dotted quarter. If you’re tapping along with this, you’re tapping twice every measure, or once every three eighth notes, once every six sixteenths, etc. You’re not tapping once every four sixteenths, i.e. not once every “quarter note”. So you have a mismatch between the tempo reference, either dotted quarter (6/8) or quarter (4/4).

I guess a guitar player interested in constant picking speed is really using the sixteenth note as the tempo reference. In a way you are going backwards. i.e. The smallest subdivision determines the pulse, not the other way around.

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Make it a waltz? Either way you’re going to have a very odd measure in there somewhere. A 1/4 or 3/8. Easier to hear it. Haha.

Yeah I know, I couldn’t think of a less clunky way hence the Dream Theater reference! For what it’s worth, for the few DT songs I can play I gave up trying to learn/rationalise the signature changes, I just … uhm … memorized the feel? (Sigh, I just became a stereotype :smiley: )

I haven’t tried the tab you posted but I’d guess it’s easier to grasp musically than to actually write it down, right?

Probably the simplest notation for this scenario is ‘metric modulation’. So you don’t need a tempo change in bar 5, you need a notation for Triplet 8th = 16th. I’m not sure if that’s possible to do in Guitar Pro, but Sibelius can handle this kind of thing.

Is this 4 4 changing to 12 8 time?

Oh totally. Play a single note at an even speed and accent every third note. Sounds like triplets, feels like triplets. Now accent every fourth note, but don’t change the speed. Sounds like sixteenths. When I do this unaccompanied I hear it as an actual change in time feel. But’s easy to do because you’re just… picking at a constant speed.

Very cool — hadn’t heard of this. This seems to get to the crux of the issue, which is that a human can’t look at a metronome number and know how fast to play, but they can try and maintain constant time and simply conceptualize the note groupings differently. If I’m understanding this correctly! Which is always debatable.

Yes, it’s not the most commonly used notation - I think the first time I saw it was an old Vai lesson:

This technique is often associated with Elliot Carter (who was not particularly concerned with making things playable for humans). ‘Night Fantasies’ is filled with frequent metric modulation creating an accel./decel. effect:

The earliest example might be in Brahms - in this Intermezzo Op. 116 No. 2 the change from 3/4 to 3/8 has a metric mod. of Dotted Quarter (of 3/8) = Quarter (of 3/4). The implication is that a bar of 3/8 should take the same time as 1 beat in 3/4.

I’m surprised!
Use accents!

Uhm, but keeping the subdivision as triplets still seems to go against the structure of the second part. I guess it could be interesting to ask a drummer: would they prefer moving from 6/8 to 4/4, or a constant 4/4 with strangely placed accents? (Which a friend told me is the Meshuggah way :smiley: )

I think the question is, if you completely eliminate all metric context, and you just tell a person to pick at an even speed, how are they actually thinking about it in their heads? That person is probably just picking “notes”, with accents on every Nth note. You can’t even really call them “sixteenths” because that implies fours. There is no time signature and there are no bar lines either. It’s just notes. The time signature and bar lines are just whatever results from the accents you’re making.

So basically you’re backing into 4/4, or 6/8, but you’re not really thinking about that. This is a case where I think staff notation may overcomplicate a little bit what a person is really thinking about when they play an unaccompanied stream of notes.

So I’d love to understand what is going on here. I can understand the concept of the metronome saying something like ♩=120/min = 500ms, and then I can tell you the exact duration of the note for most music (hopefully correctly). So if it is written in 4/4 then I’d tell you, “oh, there are 30 measures per minute,” or if they were written in 6/8 then I would say [and this could be wrong] “oh, there are 40 (= 120 * 2 / 6) measures per minute.” But my problem is that I see triplets, and I would think that each one has time ♩/3 = 168ms. But then when I see the 16th notes, I’d say that is ♩/4 = 125ms, so they are a different length. What am I missing?! :thinking:

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That’s why in @tommo’s solution you have to change triplets in sixteenths
Actually, it depends on how software treat tempo and time signature. Using BPM as a reference point for a quarter note is a common practice though it’s not a rule (I’ve seen an app that subdivided 6/8 as two beats, so in that case one beat was a dotted quarter)

All of the compound time signatures use a Dotted Quarter as the beat (3/8, 6/8, 9/8, 12/8) - these are all natural Triplet subdivisions. These all represent 1, 2, 3, & 4 beats to the bar, respectively.

Of course, you could place 3 quarters in 6/8, making it feel like 3/4 - but this is actually a syncopation or a 3:2 polyrhythm.

It’s true if talk about people, but some software treats it differently. Logic, for example, uses BPM strictly it as a quarter note duration. I believe it’s because BPM was introduced as a simple conception and noone thought that it would be used in combination with staff notation. I remember myself working in FastTracker (good old DOS tracker). There was BPM, but no time signature obviously ))

Alas, I am still confused. Pretend that you are playing sheet music. If somebody changes the metronome value on the sheet music of course I will hear the change. But if somebody changes the time signature and moves the bars around to become consistent again, will I be able to hear any difference? Right now I would say, “no.” Is that correct?

I’m not sure if you’re responding to my original question or someone else’s, but here is the scenario I encounter all the time, and it is super simple. If we’re transcribing an interview where someone is warming up in free time, we often transcribe their warmup if they play cool licks that someone might want to play. But this stuff is very often free-time, just phrases strung together. The player might play a phrase with a feel of three, followed by another phrase with a feel of four, but the picking speed for both phrases might not change. It’s just down-up-down-up and so on. As a player, it’s very easy to do this, and people do it all the time when playing free time or, again, when simply warming up. Even if your picking speed is constant, you can choose to hear something in three or four or whatever you like.

However, to write this down in such a way that a human could reproduce it, without a computer or a metronome, is not as straightforward as I would like. What I want is a way to tell the player “keep the note duration constant and just adjust the time feel from three to four”. To write this down the most tradional way, you would switch from 4/4 to 6/8, as Tommo suggested. However 6/8 is counted differently from 4/4. In 6/8 the pulse is dotted quarter, and in 4/4 the pulse is the quarter. You can’t just tell someone a new mathematical quarter note value, because nobody who is reading the notation knows how to calculate that on the fly with no computer. But everyone knows what “keep picking the same speed” means.

4 beats with a triplet feel is 12/8, not 6/8, so I’d definitely throw the latter off the table. I don’t think anyone wants to see a doubled subdivision and change of tempo for one bar either, especially if it’s just for the sake of one instrument. I’d rather see one of either:

You’ll have to set your tempo according to 8th notes because they’re the common denominator among both feels, but both of the above play back with steady 8ths regardless of time signature and no change of tempo.