Technical Term For This Rhythm Thingy?

A piece I'm working on now has some rather complex rhythms.  I have a measure of 6/8 followed by a measure of 2/4, where the eighth note is not the same between one measure and the next. Instead, the duration of the whole measure is the same from one measure to the next.  6 eighth-note beats is equal to 2 quarter-note beats.  You'd want to conduct the 6/8 section in 2, and then the 2/4 also in 2, and neither your beat pattern nor your tempo would change between the two measures.  

In the jazz I have sung before, this sort of thing is notated with a "dotted half note = half note" above the offending measure.  Brubeck apparently loved playing with this sort of rhythmic device.  It's all over his work.

Is there an official name for this sort of rhythm thingy?  Seems like there might be.  Just curious.  

All you have to do is make a metronome marking reflecting that the dotted quarter in the 6/8 measure is equal to the quarter note of the 2/4 measure. Here's a picture from the start of the 4th movement of Brahms' clarinet trio and how he handled the same thing.

Yep, that's my plan, but I didn't know if there was a technical term for this sort of situation.  If there isn't we should make one up.  :)  

A fiddle-trip?  A hemi-half-y?  A tipple-lent?  How do you tell everyone to be sure to observe the whoopee-splortch if you don't have a word for one?

how about a pateceramica-switch. it has alliteration, which is cool!

this just reminded me of a song i have to play in wind ensemble. it switches between 5/8 and 3/4 at any moment it feels like doing so. during this time, the bassoon "section" is not playing, or at least not at the right time. :P

If it's a jazz piece: Jazz + pateceramics + time switch = jazceramicuswitch (jazz - ceramicus - switch)

I thought it was called a compound meter....I might be wrong

Why not just use triplets in 2-4 time or 2-plets (opposite effect) in 6-8 time if the rhythm only lasts for a few measures?

I thought it was called a compound meter....I might be wrong

Nope, I'm pretty sure that's just any meter based on a dotted beat.  (6/8 is a compound meter because you can feel it in 2 with a dotted quarter as the main beat.)  And slip jigs play with the fact that you can "slip" between a feeling of 2 (dotted quarter, dotted quarter) and a feeling of 3 (quarter, quarter, quarter) by changing where the accents fall naturally in the measure, but without changing the 6/8 time signature.  (Yay fiddle music!)  But that's not what I'm doing in this piece.  (:

Dan, that was my first thought when I read this. I've never encountered this in music I've played, but if I as a composer were trying to achieve this effect I would use triplets in 2/4 or dotted notes in 6/8 depending on the music. As for an actual technical name though, I've got nothing.

Why not just use triplets in 2-4 time or 2-plets (opposite effect) in 6-8 time if the rhythm only lasts for a few measures?

If you were sight reading, which do you find tidier and easier to read and interpret at a glance?  It would be a case for duplets/quadruplets with some dotted rhythms within them here and there, so it's going to get pretty convoluted.  My instinct is that my original solution is clearer, but what do you think?  It will happen quite a bit, unfortunately…  

If you were sight reading, which do you find tidier and easier to read and interpret at a glance?  It would be a case for duplets/quadruplets with some dotted rhythms within them here and there, so it's going to get pretty convoluted.  My instinct is that my original solution is clearer, but what do you think?  It will happen quite a bit, unfortunately…  

Well, personally, I think the different note groupings of two or three are easier to sight read than time signatures, but that's just me.

If you've got a whole  sequence of consecutive triplets, you can get away with only notating the first triplet with a '3' and leave the others without, if that makes things neater?

The whole thing follows natural speech patterns pretty closely, actually…  Beginning students will hate me trying to read the rhythms, but it will feel pretty darn intuitive if they can figure it out.  

"The green corn follows the red plow.

The green corn follows the red plow, 

steered by the man who follows the horse.

The green corn follows the red plow that follows the horse.

The farmer thinks it's he who grows the corn,

but his horse knows better... he knows better.

The green corn follows the red plow that follows the horse.

'Twas the horse who taught the farmer how to plow.

(The green corn follows the red plow…)

Patiently walking in straaaaaaaight lines…

straaaaaight lines...

straaaaaight lines...

and the green corn follows the red plow that follows the horse...

I'll play with it and report back…  (:  Thanks guys!

Meh, yeah I knew I was wrong. My orchestra teacher used "America" from West Side Story to illustrate this rhythm thingy

It's called a metric modulation, where the beat remains consistent but the note values change according to the time signature. Very popular in 20th Century music.

I thought that term only applied if you were then setting up a new tempo, Tokke…  Using it as a technique to transition smoothly and accurately to a very strictly determined new tempo based on a subdivision of the old tempo?  Does it apply for a case like this as well, where it's only for a measure or two?  

You can modulate for a bar; it's still metric modulation!

Works for me!  Thanks all.  I'm now smarter than I was a few days ago.  (: