One key aspect of my enjoyment when I listen to music with synesthesia is the feeling of age matched with the pitch of the sound.
For instance, when I use my editing software (Adobe Premier) I can use a slider to slow the sound down, making the pitch lower. Likewise for moving the slider more toward the right. If I move it to the left, the sound gets lower until it begins going backward, when it increases in pitch again. I associate age with this.
Often I'll take a bit of music, a part of a song that I like most (something I've down hundreds of times to the early bit of the song "In the City" as mentioned hundreds of times also) and once it's slowed down, with the pitch not affected, I'll play with the pitch using that slider.
Going at regular pitch, if an instrument makes me think of something, like say, the bass makes me think of myself, then I see myself at the age of eighteen, my current age. If I were to slow it down and make the pitch lower, I get older. If I speed it up and make the pitch go higher, I get younger. Likewise for other people I think of for different instruments.
A really good way to see this is using Quicktime. Playing a video, there's an option to increase or decrease the pitch, without slowing it down. I've done this before on things I've done. I once watched my documentary completely on high pitch. Voices sounded not higher, but younger. I sounded like I did when I was nine or ten instead of sixteen. My father sounded like he did at maybe eighteen or slighter younger. Not because that's how I see it through synesthesia, but because that's how they sounded at that age. My half-brother Nelson sounded like a talking baby at age eight.
This is one of those experiences that I enjoy with music and synesthesia, because when people are thought of or involved in my thinking, it makes me see how nice it would be if their personalities stayed the same at older ages (this would be if they had awesome personalities that I love evoking through the music right now). Like they're the same wonderful person you once knew, just older and with a more experienced, deeper mentality.
By the way, the title of this post takes its name from an early Madness song.