keeping the same sound

Well, I was talking to my guitar teacher about how bands have a certain sound to them, of course the songs are different, but you can tell that it's them. SO I was saying, it's weird how that just happens. And he explained to me how record companies usually makes you keep a certain sound, because when they sign you and release a single, if someone buys your album, they'll like it, but if you don't keep that sound, they'll be like, wtf this don't sound like the band. And I was really wondering, i mean how can you regenerate a certain style so someone can tell it's you. I mean it usually just happens with me, but sometimes there are these totally off sounds from me that I get, like heavy metal, and these like jazz rock things and all this other stuff. And I don't know if any of you have first hand experience of recording with a record company, and what they "demanded" from you. I mean, because I don't know if it's a good thing to be able to have that or not, or if I get signed with a label, if I could use those sounds. Another thing is, I play acoustic sometimes (a lot when I'm doodling), and it all really is the same sound, different from electric, but my acoustic has a type of style (kind of sounds like Dashboard Confessional). Ok, this is a little overwhelming to look at, so I'll stop here, and I'll just leave it for suggestions. Thanks.

Edit:

Looks more overwhelming when typing it xD