I chose to examine the beginning of the song "On Your Way" by Alabama Shakes:
The beginning of this song has a very slow tempo, which slowly builds. It definitely engages the listener, and keeps you listening- waiting for more. There are "rising lines" in the early vocals, going from low to high pitches. At about 44 seconds into it, there is suddenly a crescendo and an increase in momentum that transitions the song into a more energetic piece. One thing that I found particularly interesting was to listen to the first 30 seconds and then skip to 2:45 into the song. There is a distinct different, and you can tell which part fits as the beginning and which part fits as the end.
I chose to examine the structure of the pop song "Oops I did it again" by Britney Spears:
The introduction to this song is very clear in the first 20 seconds, before the vocals start.
The next section, from about 20 seconds to 47 seconds, serves as the first verse but also as the pre chorus- and it builds up the song to lead into the full chorus.
The chorus is from 47 seconds- 1:10. This is the section that contains the hook/main idea of the pop song.
From 1:10- 1:28 is the seconds verse.
From 1:28- 1:40 is again the pre-chorus, and transitions the harmony into that of the chorus.
From 1:40- 2:00 is the Chorus.
From 2:00 - 2:27 there is a bit of a break in the song, with an instrumental section in the background.
Then at 2:27 the pre-chorus repeats itself but takes on a different pitch than before, and on this time on the down-beats instead of the up-beats.
At 2:53 the Chorus begins again, but you can tell that this will be the concluding chorus because it is much more dramatic and there are more vocal collisions/overlaps in this section.
At 3:22 is the conclusion, and the lead singer's voice fades out.