I can't believe I am asking this question after playing the piano for over 25 years! I seriously am confused. I know what duple meter is, but is there a "duplet" which would be counted/played differently other than the way you would count/play two eighth notes (like a "triplet" is played differently than 3 eighth notes) I have never been taught that, but that doesn't mean it doesn't exist.

I'd have to see it in the context of a piece to be able to tell you what to do. However, it sounds as though you are asking if something like that exists. Sometimes if you are in a key signature like 6/8 (or any other compound meter) you will see a "2" between two 8ths, and this means to play them as if two of those notes can fill a beat (rather than 3). I believe that's right, anyways.

In "swing" two eighth notes are played like a triple quarter followed by an eighth. Written as duple but played as triple.

However, there is usually some direction telling you to make that change.

Morodeine: I'm referring to Clair de Lune, right at the start, in meas. 3 -- there are two groups of two eighth notes with a 2 in brackets above them. So, this would seem to indicate they are played differently than a normal set of 2 eighth notes. (It's compound meter: 9/8) It's funny, I've played tons of difficult repertoire, and have a BA in Music ed, but have never been taught or come across a duplet. I even googled it and went through half dozen books, which explain what it is, but not how it is played.

Gary: what is "swing"? You mean, swing music? thx.

Morodeine, I'm still a little confused. Do you mean that normally in compound metter, such as 6/8, each 8th note would get one beat, however with the two in brackets above 2 8th notes, those two 8ths notes would get ONE beat?

Technically the dotted crotchet is the beat. 6/8 is viewed as 2 beats of three quavers, rather than 6 beats. It simply means that sometimes that beat is split into 2, rather than 3.

6/8 has two beats
9/8 has three beats

Each beat is a dotted-quarter note long, and the beats are typically divided into threes. 6/8 is a duple meter (you count 2 dotted-quarter beats) and 9/8 is a triple meter (you count 3 dotted-quarter beats.)

Theory textbooks call 6/8 a duple-compound meter and 9/8 a triple compound meter. (In compound meters, the beats divide into threes instead of twos.)

Now, in the case of Clair de Lune and other pieces with duplets, the duplet changes the subdivision. You still count three beats in the measure, but the beat with the duplet will subdivide differently (into 2 instead of into 3 sounds per beat.)

I like your analysis but fear it will not be understood by students. I would not even attempt any further explanation in this medium. It seems to me to be one of those things that is very easy to explain with a demonstration, in person, but nearly impossible with only words.

For now consider that as right. It is a little more complicated, but I think it will work.

However, I don't want to confuse you. Your question was about something different. In the Debussy, the music is set up in beats that are divided into three parts, so three eight notes. Whenever a time signature has an "8" on the bottom and a top number that is 3, 6, 9, or 12, you know that this the is "default" rhythm for that piece.

Any time a different number of notes are fit into a beat, it is called a "tuplet". When Debussy is doing pairs of 8ths, he marks them as a "2 eighth tuplet", and that means that those two eigths fit into the same amount of time as 3 normal eighths, for that piece. Remember the norm is 3 to a beat.

Now, did I make it better of worse? I can explain this very well in a lesson. Here it is very frustrating.

Yeah, to be honest, it's not something that you can easily count. Generally I prefer students to fully understand everything, but a duplet is one of those things that can only be played through being felt (unless you go so far as to think of it in terms of a cross-rhythm, where the note falls halfway between imagined triplet note).

Heh...I'm in the same boat. In person, it would take me all of 5 minutes to completely and forever answer this question with pristine clarity.

But alas, it's the internet...

Kreisler, Gary, and Nyireghyhazi - I totally understand now! I understood about duple, triple, etc. meters, but that set of 8ths in Clair de Lune left me wondering "what do I do with these?" It makes perfect sense that they would comprise one beat. THanks for taking the time to explain it.