Beat andmeter are rather easy to understand.Oddly rhythm is a bit more complicated.Rhythm is the organization of timeinto compelling patterns of long andshort sounds.Here's a famous melody,one created by the Frenchcomposer Maurice Ravel fromhis ballet Bolero of 1928.There is a tune, a succession of higherand lower pitches, shown vertically.And, there is a rhythmmoving left to right.Now let's strip away pitch andleave the rhythm alone andit will look like this,as we see on our next slide.But what we hear first at the beginningof Bolero is not the melody, butanother rhythm, this one.And it's played by a snare drum.Now, a snare drum, as you may know,has no particular pitch.It just plays a rhythm, pure rhythm.I'll tap it.[NOISE] And that's allthe snare drum player does.So he better like that pattern,going to be doing it the next 14 anda half minutes.Now beneath the snare drum pattern,low strings play another rhythmicthat provides something of a harmony.Let's take a look at that now.Bum.[MUSIC]And, so on.Eventually, the flute entersadding the enchanting melody.So now we have three rhythmsoperating here, one in the flute,which also carries the melody, one inthe snare drum, which is a simple, orpure, rhythm, and the third in the bass,which is providing something ofa harmony below the melody up above.So we have three rhythmsthat are staying within andemphasizing the structure of the measure.Three different rhythmssounding simultaneously,three different patterns of longs andshorts.Let's give a listen to the SouthKorean Philharmonic Orchestra as itperforms this work.I like the recording engineering here.It's very easy to hearthe three musical parts.[MUSIC]So who's playing the beat here?Well, no ones actually playing the beat.About the only time an instrumentplays the beat in music iswhen the bass drum in a marching bandplays the beat, or maybe a drummer ina rock band playing the bass drumby means of left foot on a pedal.So how is it then that we hear the beat?Well, we hear.[SOUND] Well, our ear,actually our brain digeststhis complex of information andextrapolates it from it,a basic structural frameworkunderlying the music.It's a kind of platonic meta reality oroverarching structure that noone actually hears, orno one actually sees, but it's there.But we do hear the beat.And we hear the beats organizedinto groups of three.[SOUND] One, two, three,one, two, three, and so on.Bolero is written in triple meter.We feel the triple meter.And that's all that really counts.But if we want confirmation of thiswe can look at the musical notation,particularly the base, where wesee clearly three quarter notes orthe equivalent of threequarter notes in each measure.Why do we hear it is triple meter?To see how that works,let's turn to a class video demonstration.[MUSIC]What, what, what's the key here?What did you listen to?How, how many think it's in duple meter?Raise your hand.How many think it's in triple meter?Okay.Almost everybody thinksit's in duple meter.And that's correct.Now we worked through thisjust a little bit once before.What is it that tells usthat it's in duple meter?It's the bass.[MUSIC]Because it's organizing itselfvery strongly in duple patterns.There's one other interestingthing in here, this would be.Well, let, let, let's, let's think throughthat in one in one additional way.And that is.Notice that in duple meter wehave a strong beat, right.Strong, weak, strong weak, strong, weak,strong, weak, strong, weak in that sense.Or if we have triple it would be strong,weak, weak, strong, weak, weak.It would be two weak beats, ortwo unstressed beats,between each strong beat.We could do this.[MUSIC]And we'd have The Waltz of the Bulldog.>> [LAUGH].>> It'd be pretty cool to see, actually.So there it's, I'm simply takingthe Cole Porter piece andthrowing in an extra beat in each measure,an unstressed beat in each measure, andit works out pretty well.Notice, this would be,Harvard would have had a,had a field day with this melody if he,Cole Porter had not done one thing.He, he, he makes this really rathersnappy by the use of this kind of stuff.[MUSIC]We come in on bom, bom, bom, bom, and thenda, da, da, da, da, da, da, da, da, da.What's that a good example of?>> Syncopation.>> Syncopation, yeah.Term's on the board up there, butit's a good example of syncopation.Sort of jumping in ahead of time, cuttingoff the beat, getting in there aheadof time and throwing off the metricalbalance for a very short period of time.Okay.Let's see now if you can hear thedifference between duple and triple meter.I'll play two examples.[MUSIC]That'snumberone.Here's another one.Which is duple?Which is triple?[MUSIC]Right.First one was triple.Second one was duple.How'd you do?Well, here's one more.Let's try another one.One last, one last one of these.You'll like it.First there was music by Handel.That was this piece.[MUSIC]That's our triple meter piece.Then we had music by Schubert.This is our duple meter piece.[MUSIC]Let's try one other one.What about this one?[MUSIC]And soon.Right again.Triple meter.[MUSIC][SOUND]