To keep your place in a song, you must concentrate. This might sound like advice from a Musicianship 101 class, but you really have to do it—as a bass player, keeping your place and outlining the form is your most important job. Imagine a band jamming away, the saxophone player blowing his best solo ever, the drummer digging in and bashing out the groove, only to have the bass player jump to the bridge eight bars too early. Bummer. “What a bozo,” they’ll think as they turn to the bass player with half-hateful grins. It sure takes the steam out of a performance when someone gets lost.

Form is easy to understand. Mathematically speaking, many basic forms are organized in powers of two, usually in the form of two-, four-, eight-, 12-, 16-, and 32-bar sections. Most standard jazz and pop tunes are structured this way. Let’s look at a few specific examples of chord charts, and how to recognize the form.

The chord changes of the Duke Ellington classic “Perdido” (Ex. 1) provide the basic structure for many other standard jazz compositions. The form consists of an eight-bar A section, which is repeated (the second A), followed by an eight-bar B section (the bridge), and finally a reprise of the first eight-bar A section (called the last A). The bridge jumps out because of the chord change to D7, but the three A sections can run together unless you concentrate and know where you are at all times. To lock the form in your brain, say “top,” “second eight,” “bridge,” and “last eight” silently to yourself each time you start a new section.

AABA is a tried-and-true song form for improvisers. Countless standards, like “Body and Soul,” “Georgia on My Mind,” “Take the ‘A’ Train,” and “Softly as in a Morning Sunrise,” to name just a few, are based on the AABA form.

John Coltrane’s “Impressions” and Miles Davis’s “So What” also share the AABA form. Both of these compositions have the same chord structure: eight bars of Dm7, eight of Dm7, eight of Em7, and eight of Dm7. The hard part about playing these changes is that there are long stretches of a one-chord sound. It’s easy to zone out in Dm7 and forget whether you just played the last eight bars, or the first eight bars. Remember to concentrate, count, and call out the sections to yourself.

Some compositions are slightly uneven in form. “All the Things You Are” has an ABCD form (8-8-8-12), with the D section being similar to A but with a four-bar extension. You can keep your place in this form easier than in a tune like “Impressions,” even though there are more chord changes. In each section of “All the Things You Are,” you start in a different key, which creates an automatic landmark for your ears.

In the 1960s, saxophonist Wayne Shorter stretched the idea of form in jazz composing with songs like “Yes and No” (AABA, 14-14-16-14) and “Infant Eyes” (ABA, 9-9-9). The best way to follow these tunes is to keep the melody going in your head—you are playing a bass line on the chords, and the chords are harmonizing the melody. Sing the melody to yourself!

Saxophonist Benny Golson has given us many jam-session favorites with unusual forms, like “Stablemates” (ABA, 14-8-14), and pianist Horace Silver has contributed great standards like “Nutville” (ABC, 8-8-8; see Ex. 2). The trick in “Nutville” is to remember that the last two bars of Cm7 don’t mark the beginning of the form, even though the groove goes back to the original Latin feel. When you get to that point in the tune, count to yourself and then say “top” when you go back to A.

There are standards with even longer forms that jazz musicians like to play: “Cherokee” (AABA, 16-16-16-16), “Caravan” (AABA, 16-16-16-16), “Night and Day” (AAB, 16-16-16), and possibly the mother of all standard song forms, “Begin the Beguine” (ABCDEFG, 16-16-16-16-16-12-16). You won’t find this classic Cole Porter rumba being called on jam-session night at the local jazz club, but it is often played at society gigs when the beautiful people get up to do their lizard dances.

To start exploring form with easier jazz standards, take a look at “Cantaloupe Island” (ABCA, 4-4-4-4), “St. Thomas” (AABC, 4-4-4-4), or “Summertime” (ABAC, 4-4-4-4). To keep your place in “Summertime” (Ex. 3), look at the chord that begins each four-bar section. The first chord in A is Dm7. The first chord in B is Gm7. The repeat of the A section in bar 9 begins on Dm7 like the first A. C, the last four bars of the form, begins on Fmaj7. Once you know where each section begins, you are on your way to hearing and feeling the musical landmarks in the form. Memorizing the whole progression is now just a matter of filling in the harmonies between those landmarks.

In contrast to the standard way of improvising over changes, the jam-band style of playing moves in and out of a set form using vamps. A vamp is just a small set of chord changes, or even a simple riff, that is repeated over and over. When a solo is finished, or when someone gives a cue, then the band jumps to the next section—maybe another vamp or maybe another set of changes. Jazz players might use a vamp as an intro before the melody, at the end of a tune, or as an interlude between solos. A vamp can augment the form of the tune, either in a predetermined way—written into the arrangement—or improvised in the heat of the musical moment.

Always look at the form of a new song; you’ll learn the song faster. Take songs that you already know and check out the form. You might be surprised at the simplicity—or complexity—of your favorite songs. Above all, remember to concentrate on keeping your place, and you’ll always land on your feet.