Thus far, we've discussed the function of verses and choruses, and what can help make a chorus work more effectively. Today, we'll talk a little about two additional, less common parts you can incorporate into your songs: the bridge, and the breakdown.
Although technically different, bridges and breakdowns both serve a similar purpose: namely, to act as a sort of musical 'palette cleanser' to keep the listener's interest and provide some variety over the verse and chorus parts in a song. Both parts achieve this end in different ways, however.
A bridge can almost be thought of as a secondary verse. With vocal music, there are usually lyrics during a bridge, often acting as a turning point in the lyrics or providing further emphasis on the theme of the song. That said, an instrumental or solo section can be a bridge as well. What's important is that the bridge differs musically from the chorus and verse sections. The aim of the bridge is simply to provide some more variety to the song and break up any potential monotony of just sticking with a simple verse/chorus structure. Bridges are nowhere near as common these days as they once were, but it is good to be familiar with their use anyway, as sometimes it really contributes to the strength of a song.
A breakdown (or drop, as it is sometimes called), on the other hand, has the same function, but achieves it by manipulating the energy level of the track instead of the melody or chord progression. It's most often heard in club-oriented electronic music, but it can be found in rock music sometimes too (think of any song by Boston where all the instruments drop out except the rhythm guitar, for example). Breakdowns usually follow a rather busy part of the song. When you remove a large number of elements at once, this causes a very noticeable change in the energy. Gradually, elements are re-introduced a bit at a time (for instance, every four bars), until the arrangement builds to a crescendo (often through building drum rolls) and at last the full arrangement kicks in again. Done correctly, it can really increase the excitement of an arrangement and work brilliantly in a live context. This is another example of 'teasing' the listener. One really effective thing to do in a breakdown is to take whatever the main hook of your song is and just have it play the first, say, three notes of the hook over and over, eventually adding more of the notes as the breakdown progresses until finally the full arrangement kicks in again with and you allow the hook to play through properly.
Because the function of both song parts is to shake things up and hold the listener's interest, you often find bridges or breakdowns before the final verse or chorus of a song. Again, you can change this up (my song "Decades", for example has a breakdown before the FIRST chorus), but there's a reason you'll find these parts near the end of a track more frequently than not: it just works best that way usually.
As with any portion of a song, it is important to pay attention to the length of a bridge or a breakdown. A bridge, in general, should be about the same length as one of your verses. A breakdown, on the other hand, actually needs more time to work properly since you are building up the track from next to nothing a little bit at a time. 16 bars would probably be a minimum in most cases, with 32 bars being more common. The key with both is not to let them overstay their welcome. If you string the listener along too long with either, they are likely to lose interest and you end up defeating the purpose of having these parts in your song at all.
What are some of your favorite examples of bridges and breakdowns?