When sound events happen at regular intervals of time, the music’s patterns take on a pulsing, measured quality, making it easy to tap, conduct, or count aloud at an even speed as we're listening. We say the music has a steady beat; the speed at which we count or tap is the tempo of the music. However, this quality of regular patterning occurs in varying degrees. Fairly strict periodicity (recurring at regular intervals) may be heard in dance and march music, minimalist repetitive structures, and in electronic-based pop music. Other styles call for relative freedom from regularity; the music sounds unmeasured and it may be difficult to tap a steady beat. Music of this type includes liturgical chant, opera recitative, the opening improvisatory section (the alap ) of Indian classical music, and much twentieth- and twenty-first-century Western art music. Music at the extremes, that is, exhibiting only precisely measured, strictly periodic rhythms, or, conversely, sounding totally free, and non-pulsed, is rare. Most music falls somewhere on a spectrum between these extremes, and consists of both measured and unmeasured qualities.
Listen to the music listed below in Example 1a. Consider where each piece might be placed on the line in Example 2, from totally unmeasured on the left, to strictly measured on the right. Notice how your impressions may change as you listen more than once to some of these examples. It may be difficult to order these excerpts precisely along the spectrum from unmeasured to measured; however, your understanding of the music will deepen as you consider the rhythmic qualities of each excerpt compared to the others.
[[Italicized text, as above, is directed to students, to be guided by the instructor, in class.]]
Example 1a. Playlist of music of unmeasured, measured, and mixed qualities
Example 2. Spectrum of unmeasured to measured music
When we look at a score using traditional notation, it may seem like the music is quite strictly measured, with little variation from the established beat. Such indications as ritardando, accelerando, meno mosso, or ad libitum, however, can be used by the composer to suggest deviations from absolute regularity. In fact, in performance, rigid adherence to the proportions of notation is rare, and would be described as mechanical and unmusical. Even when terms to vary the tempo (speed of the beat) are absent, we introduce both subtle and not so subtle variations to perform convincingly. We call the process of applying these variations, whether conscious or not, rubato or tempo rubato. The application of rubato in performance lends a desired flexibilty and expressiveness to music which may otherwise sound too rigidly measured. You will have heard rubato in several of the excerpts above.
We recognize two kinds of rubato: the first, indicated by terms like ritardando and accelerando, is a speeding up or slowing of all elements in the music, as in the Chopin Nocturne. The second refers to pushing ahead or lagging behind some component of the music that is keeping a steady beat. At some point, the time taken away from the steady tempo (“rubato” is the Italian word for “robbed”) will be made up and the coordination of parts resumes.
Shirley Horn’s rendition of Georgia on My Mind is an excellent example of this type of rubato. Sing the melody as written below and then compare it to Ms. Horn’s rendition. Listen for the relationship of her melody to the piano, bass, and drum support heard “under” the voice.
Ex. 2a. Hoagy Carmichael. Georgia On My Mind.