#1 - It sounds firstly like it does inside the songwriter's head.
#2 - It sounds like it does inside the band's head(s).
#2a - It sounds like the bandleader thinks it should.
#3 - It sounds like the band's manager thinks it ought to sound for their image, and to make him money.
#4 - It sounds like the producer thinks it needs to sound, to "shift product" and also often to carry his "trademark sound".
#5 - It sounds like what the engineer believes to be his best attempt at balancing all the other opinions that have been shouted at him into account, and still making it sound musical.
Not strictly true, obviously - I'm having a bit of fun too - and not applicable to each and every recording, but as a huge generalisation it definitely contains large grains of truth.
As a rule of thumb, if you're in the studio for any length of time, take the engineer out for a beer. He/she will be the last "creative" person to touch your work, and you REALLY need him/her on your side. A good engineer will play the studio almost like a musical instrument, and you definitely want him/her in your band and nobody else's.
As I've said, everybody involved with a song quite possibly hears it differently, even before laying the track down in the studio.
Different members of the band will even hear it differently while performing it live, or rehearsing it, especially, perhaps, you're the bandleader (BL), whose "job" it is to hear the aggregate of all the players and tweak the little things that HE thinks are missing, or "wrong" with the way the song is being played before it even reaches the studio. But, and trust me on this, playing live and rehearsals can sound like two different songs. The BL has to decide which bits (if any) from both situations can be translated to the studio. Some bands react better to playing "live" in the studio, and adding any overdubs after the fact, while others will actually perform better by building a song track by track, maybe starting with a click-track to guide a basic rhythm track for the other band members to, eventually add their parts to. Often, the basic rhythm track does not make it into the final mix.
As for the musicians, often, the only other instrument that the drummer is interested in is the bass, and vice-versa, because they need to "lock", becoming a single unit, in effect becoming the "spine" of the band, although the bass-player might show an interest in the keyboard player if he's stepping on the bass lines. The singer and lead guitarist are only interested in themselves, and definitely not each other. It's a contest FFS.
The rhythm player and the keyboard player are often expected to suffer in silence and do what the BL says.
As I said, not exactly serious, but there are bits 'n' bobs that I think many musicians will recognise if they've ever gone further than playing in their bedroom.
Of course, with the advent of professional-quality home recording software, and "plugins" that emulate everything from a synth to a guitar, to a whole orchestra, it's become easier to cut out some of the middlemen, and hopefully, the songs are turned out as the writer and performer wants them to sound, for better or worse.
Of course, if a song is picked up by what used to be called a major record company, the cycle begins again.
Self-releasing, or licensing recordings, is about the only way you're likely to hear what the songwriter actually intended, or, hopefully, a close approximation thereof.
Of course, that's not always a good thing, as I've proved endlessly in the past, with my own home-studio setup.
I hope you've enjoyed my bit of fact-laced fun.
