What is Rhythm?

Stupid question, isn't it?

/We all know what rhythm is -- at least we know if when we hear it and feel it. But what is it really -- what makes rhythm tick? Wikipedia defines it as "any measured flow or movement, symmetry" - in other words, it is the variation of the length and accentuation of a series of sounds or other events.

The sun, for example, has a rhythm. It comes up every morning and goes down every evening. Steady. The earth has a rhythm too, as it revolves around the sun. We call that rhythm a "year." Your heart has a rhythm too -- if you take your pulse you'll see it is quite steady. All of nature has rhythm, and so it is quite natural that music has rhythm as well.

We speak of that rhythm in terms of "beats", and we measure those beats using tools such as "time signatures", "quarter notes", "eighth notes", "syncopated notes", "steady notes", etc, etc, etc. Most music is in either 4/4 time or 3/4 time, although there are many other varieties that are not used nearly as music.

To master rhythm a person needs to have a "baseline" by which to measure the notes that are occuring in various patterns.

Rhythm Piano

How Time Signatures Work in Music Rhythm

Time signatures are the area of western musical notation that give specifics about time and how it will function within the song. The importance of these two numbers is apparent by their placement alone; time signatures are literally the second thing a musician sees, after the clef. One glance at the time signatures and the musician is able to put the entire song into context; not only do time signatures denote rhythm, they can also tell quite a bit about style and genre.

Time signatures consist of two numbers placed vertically on the staff. They appear right after the key signature (if there is one) or the clef (if there isn't). Each number says something different about the piece of music: the top note indicates how many beats are in one measure of music, the bottom indicates which type of note makes a beat (or "gets the beat," in musician-speak). For example, times signatures of 4/4 tell a musician that there are four beats per measure of music and that the quarter note is one beat.

But time signatures aren't always so easy. The above explanation only applies to one type of time signatures, simple time signatures. 4/4 is the most common of the simple time signatures, but 3/4 and 2/4 are used frequently, as well. The other type of time signatures, compound time signatures, tends to be a bit more complicated. Compound time signatures are recognizable by a top number of six or higher that is always divisible by three, like 6/8. To figure out how many beats exist per measure, the top number is divided by three; so in 6/8 time signatures, the top number wouldn't say that there are six beats per measure, but rather two. Likewise, the note type is found by multiplying the bottom number's note value by three; an eighth note doesn't get the beat in 6/8 times signatures, but the dotted quarter note does (a quick note: the note value in compound time signatures will always be dotted). 6/8 and 12/8 are two of the most common compound time signatures, used heavily in waltzes and blues, respectively.

But even compound time signatures don't cover the broad spectrum of rhythms that time signatures have to offer. No, there are still times that a rhythm is so odd, so seemingly offbeat, that the time signatures must be similarly irregular. And that's how we get to irregular time signatures, time signatures that can be categorized into simple or compound, but because of their rare usage and strange rhythm aren't really categorized as such -- like 5/8 or 10/4. Time signatures like these are found pretty frequently in innovative rock and pop groups. The most famous examples of irregular times signatures are found all over Pink Floyd's "Dark Side of the Moon," but bands like Rush and Genesis (early Genesis, before Phil Collins stepped away from the drums) have also used them to marvelous effect.

What does "metre" mean in terms of musical rhythm?

Metre divides music into measures of beats that are stressed or unstressed, accented or unaccented. These measures are what a song is made of; think of them as rhythmic building blocks, building blocks that have been built by metre. Using divided sections like these helps to define exactly what part of the metre is to be accented and adds structure and organization to a song. But these building blocks can't outshine the metre itself; measures may be the bookshelf, but metre is the books that fill it. It is, simply, rhythm. Beats. The backbone of a song that, without it, would be messy and chaotic (exempting, of course, some experimental music that strives to be so).

The metre of a song is indicated by that song's time signature; metre is the physical form of that notation. Just as a note is the written form of a pitch, time signature is the written form of metre. It gives us the specifics of a metre, but doesn't replace it. Understanding how time signatures function in the way that they do is the very basis of metre.

A song's metre is understood by two elements: how many beats are in one measure and what type of note constitutes one beat. A 4/4 metre, for instance, has four beats per each measure with the quarter note making up one beat. A 3/4 metre has three beats per measure with the quarter note making up the beat. A 6/8 metre isn't read like this, however; it has two beats per measure with a dotted quarter note making up the beat. This type of metre, the kind shown by a time signature with a top number of six or higher that is divisible by three, are compound and found by dividing the top number and multiplying the bottom number by three.

Metre comes in tons of forms, straightforward or syncopated. A 4/4 metre is the most common, used almost without exception in rock and pop songs because of its straightforward beat that makes writing to it (and following it) very easy. 3/4 metre is the second most common, creating a swingy, syncopated beat; this is also found in rock and pop songs, most typically in slower ballads. 6/8 metre is home to the waltz, 12/8 metre is used by blues musicians, and 2/2 metre (also called cut time) is what marches are made of. But other sorts of metre, like 6/4 or 5/8 or even 13/4, are often used to innovative effect, creating an effect that makes the rhythm hard to pin down. Though this type of metre, known as irregular, are largely known for being hard to follow, some musicians have made it clear that a song does not have to be in 4/4 to be catchy. Consider Dave Brubeck's "Take Five." Sure, it isn't 4/4, it has an offbeat nature, but it certainly isn't hard to follow, and those 5 beats per measure kind of keep us constantly surprised. The metre provides the heartbeat, and the rest of the song follows it; if that heartbeat keeps going strong, the listener is bound to follow it as well.