Time in music is relative to a constant, steady pulse called a tempo. In a popular music context, this pulse is usually provided by a drummer or percussionist and in classical music it is often provided by a conductor. Tempo is measured in beats per minute, or BPM. A steady pulse can be generated by a device called a metronome, used as a practice aid and tempo reference. The timing of notes relative to a steady tempo is known as rhythm.
In notated music, each note is assigned a rhythmic value, which can be determined from the shape of the notehead and it's stem. The longest note value used in most music is the whole note, which receives four beats and looks like an empty oval with no stem. The chart below shows a whole note and all of its divisions into smaller note values.
The first value below the whole note is a half note. As you can see, the half note consists of an unfilled oval with a stem attached. As its name suggests, a half note receives half the value of a whole note, which is two beats. Fill in the oval and you've got a quarter note, which receives one beat. The next note looks like a quarter note but has a little flag protruding from the stem. This is an eighth note, which receives one half of a beat. Add another stem and you've got a sixteenth note, which receives one quarter of a beat. You could keep adding flags to create 32nd, 64th, and 128th notes; each flag cuts the note value in half. To reduce clutter, flagged notes are often groupled together with a beam when they occur together, as in the example below.
The specific rules for beaming notes together are beyond the scope of this series. As for those vertical lines, we will cover those in the ext section on meter. For now just worry about learning to recognize all of the different note values.
You may be wondering how to represent note lengths that are between the values defined above. There are two ways of doing this; with ties or with dots. A tie is a curved line that connects two notes together. Two tied notes receive the combined values of the individual notes. For example, a quarter note tied to a sixteenth note receives one and a quarter beats. Adding a dot to a note adds half of that note's value. For example, a dotted half note receives three beats. The excerpt below shows two rhythmically identical passages, one using ties and the other using dots.
The decision of whether to use ties or dots to represent a rhythm comes down to whichever is more clear; some rhythms are easier to read if tied while others will be easier if dotted. In general, dots are preferred because they make the music look less cluttered.
While notes let us know when to play in a piece of music, rests let us know when not to play. Each note value has an equivalent rest, shown in the table below.
The whole rests consists of a rectangular box that hangs from the fourth staff line. Just like the whole note, the whole rest receives four beats. The half rest is identical, but instead of hanging from the fourth staff line it sits on top of the third. The quarter rest consists of a crooked line in a backwards "S" shape, and the eighth rest is a slanted line with a single flag. Just like with notes, you can continue to add flags to the eighth rest to create 16th rests, 32nd rests, and beyond. Rests can be modified with dots to reduce clutter, but ties are unecessary with rests.
That's it for Part II of the How to Read Music Info Barrel series. In Part III we will talk about meter and counting. What we've covered in part two may seem like a lot to take in but, believe it or not, you're actually most of the way there! To practice recognizing note values, go through a piece of sheet music and write in the value for each note. Recognizing note values will get a lot easier once we learn how to count rhythms in the next section. Now, here's a review of the vocabulary from this article:
- tempo: A steady pulse used to keep time in music. "Tempo" is the Italian word for "time."
- BPM: "Beats per minute;" a unit for measuring tempo.
- metronome: An electronic or mechanical device which provides a steady tempo.
- rhythm: The timing of musical notes relative to a steady tempo.
- whole note: A note that receives four beats.
- half note: A note that receives two beats.
- quarter note: A note that receives one beat.
- eighth note: A note that receives on half of a beat.
- sixteenth note: A note that receives one quarter of a beat.
- beam: A bar that groups multiple flagged notes together.
- tie: A curved line that connects two notes, adding their note values togeteher.
- dot: When added to a note, a dot adds one-half of that notes value.
- rest: A symbol that instructs the player not to play; the opposite of a note.