I was listening to this song by Mumford and Sons and realized that I am a big fan of the slow build. This song starts soft until the crescendo midway through. My experience with the slow build is that it tends to emerge out of repetition. They hammer it home as the energy builds. It's also a nice touch to soften it up for the ending.
Playing songs for people is always tough because you are always way more excited about the music than the other person. They are normally like "yeah this is pretty cool" and then try to talk to you about some other subject, but you are like, "wait wait check this part out is really good". I think this is especially true of songs that have the slow build, becuase you can sense them getting impatient and you are like "no wait it gets really good just hold on. It like crescendos and then there is this part where it is really loud". I am paraphrasing of course, other people probably sound way more intelligent when they are describing the music. It's normally better to play it cool and act like you don't care if they are paying attention or not. This next song has a long wait time for the slow build (if you are super impatient it starts about 5 minutes in):
Classical music has of course been doing the slow build for years. I remember first hearing this next one when I was in high school. I was so excited because when it started on the CD you could almost not hear what was happening. Sometimes the range on classical music is so great it is difficult to to listen to in recorded form. You constantly have to adjust the volume nob. We performed this piece (Enigma Variations) when I was in college and Cali said it moved her to tears. Apparently, when I saw her after I said something cynical about the crying (sorry Cali):