Examples:

• A fast bebop tune may be played at 200-300.
• Beats are grouped into measures, also called bars. As with the beat itself, the measure itself has no explicit representation in the sound, but the repeating pattern of beats underlies everything that is played. In the following example, there are four beats per measure.
• Four is the most common number of beats per measure, although three is not unusual.
• Measures are marked in written music with vertical lines called bar lines.
• The tempo is normally marked at the top left, either in absolute terms of beats per minute, or with a phrase in English or, in classical music especially, in Italian. Tempo markings in Italian include, from slowest to fastest, largo, larghetto, andante, allegretto, allegro, and presto. In jazz, the tempo marking is usually in English and is often combined with some indication of style, such as "fast swing" or "medium slow bossa nova".
• After the tempo, the next indication of rhythm is the time signature, which is a pair of numbers arranged vertically toward the left edge of the first staff.
• The top number indicates the number of beats per measure. The bottom number indicates the type of note that corresponds to the beat. Most often, this is 4, indicating the quarter note gets one beat. Whenever a quarter note occurs in the score, this indicates that the musician is to play a note that lasts for one beat. A quarter note is notated as.
• It has already been observed that 4 is most common number of beats per measures and that normally the quarter note gets the beat. This is a time signature of 4/4, also referred to as 4/4 time or common time. One possible rhythm for a typical measure in 4/4 time would be four quarter notes. Each quarter note would get one beat, adding up to four beats in all:
• A note that gets two beats in 4/4 time is called a half note, and it is notated as.
• It takes only two half notes to fill a measure in 4/4 time:
• Or, a measure may contain one half note and two quarter notes:
• A whole note gets four beats and takes up an entire measure in 4/4 time:
• A note that takes half a beat is called an eighth note. A single eighth note is notated as:
• Eighth notes often occur in pairs taking up a full beat; this is notated as:
• Larger groupings of eighth notes are used as well, such as four eighth notes taking up two beats:
• In jazz, recall that eighth notes are generally swinging. While some people try writing this out using triplets or dotted-eighth / sixteenths, the more common practice is to simply notate eighth notes and depend on the player to interpret the swing:
• A beat may be divided into four parts; a note that gets a quarter of a beat is called a sixteenth note, and is notated singly as or in groupings as:
• In general, one can continue to subdivide the beat into thirty-second notes, sixty-fourth notes, and so forth; these are notated simply by adding more stems or beams:
• If a beat is divided into a number of equal parts that is not a power of two, then this is notated using a tuplet. Most common is the triplet, which indicates three notes per beat:
• Similarly, an eighth note or half note might be divided into three equal parts:
• The full form of a tuplet allows the composer to specify a ratio giving the number of elements in the tuplet and how long the tuplet is to last. For example, the simple triplet discussed above - three notes in one beat - is notated with eighth notes, which normally occur two to the beat. The full form of the tuplet is then:
• A dot may be added to the right of a note to indicate its length is to be increased by half. For instance, a dotted half note lasts three beats: two for the half note, and an additional one (half of the original two) for the dot.
• A common idiom is a dotted eighth, which takes three-fourths of a beat, followed by a sixteenth note, which takes one fourth. This is notated as:
• Additional dots may be added to indicate a further lengthening by half again as much. A double dotted half note, then, lasts three and one-half beats: two for the half note, and additional one for the first dot, and an additional one-half for the second dot:
• A note that extends over a bar line or otherwise cannot be represented by the note lengths described above can be represented by ties. When two notes are tied together, this indicates the second note is not to be sounded separately, but instead should be treated as a continuation of the first:
• Notes such as any of those described above are meant to be played. If the musician is supposed to refrain from playing for a number of beats, this can be indicated via the rest. There are rests corresponding to all the various note lengths:
• A typical measure contains a mix of notes of various lengths as well as dots, ties, and rests:
• The time signature is also called the meter. Sometimes the meter may change within a composition. This is indicated as follows:
• While the quarter note is the usual unit for the beat, it is not uncommon to use the half note or the eighth note. When the half note is the basic unit, the number 2 appears at the bottom of the time signature. A measure written in 2/2, also called cut time, looks identical to a measures written in 4/4 time. That is, four beats of quarter notes could also be interpreted as two beats of half notes. Cut time is often used to indicate an underlying half time feel, meaning the bassist will tend to play only two half notes per measure rather than four quarter notes, and the drummer will alter his part accordingly as well:
• When the eighth note is used as the basic unit, the number 8 appears at the bottom of the time signature. The most common such time signature is 6/8. In 6/8 time, often the eighth notes are grouped into two sets of three. This is sometimes referred to as compound meter. The underlying feel is that of two beats per measure, each divided into triplets:
• Similarly, in 9/8 time, the underlying feel is generally that of three beats per measure, each divided into triplets as well: