Yes, the word for those jazzy extra sections at the beginning of Cole Porter songs is "intro". The intro is a musical section that precedes the main part of the song, usually with a distinctive melody and rhythm. It is often used to establish the key, tempo, and mood of the song, as well as to capture the listener's attention and set the stage for the vocal or instrumental performance that follows.
According to music experts, the use of intros in jazz and popular music can be traced back to the early 20th century, when composers and arrangers began experimenting with new forms and structures. Some of the most famous intros in jazz history include those of Duke Ellington's "Take the A Train," Miles Davis's "So What," and John Coltrane's "Giant Steps."
In the case of Cole Porter, many of his songs feature memorable intros that have become iconic in their own right. For example, the intro to "I Get a Kick Out of You" features a series of ascending chords that create a sense of anticipation and excitement, while the intro to "Night and Day" features a distinctive rhythmic pattern that sets the stage for the song's romantic lyrics.
Overall, the use of intros in music is a creative and effective way for composers and arrangers to engage listeners and establish the mood and tone of a song. Whether they are jazzy and complex or simple and straightforward, intros play an important role in the musical landscape and contribute to the rich history and diversity of musical expression.