Yup, comparison with a similar style is a good starting point; but really it is down to the song.
With the vast majority of things, he vocal will be the most important part of the mix, and therefore should be the clearest thing in there. If you leave the level even a little too low then some things may be masked and in most cases this is not what you want. That said if you tur it up to far, you are going to turn them up too far, they will seem too up front, which except in certain circumstances is not really helpful.
So you see the problem. It's all about balance. Listening to a variety of recording will help, different styles will use different relevant levels. This helps in getting your ears getting tuned into the right sort of sound.
Perhaps the most important thing is to think about vocal mix BEFORE you get to the mixing stage or even to the recording of he main vocal line. Recording a Ghost/guide vocal is basically a must. This will help when you come to recording the other instruments, as if something seems to overpower or clash you will notice it while recording it (hopefully) rather than finding out too late.
Another way of ensuring the vocal sits within the mix (ie not too loud but still clear) is using some clever EQ'ing. This is little tricky to explain so bear with me...
This process is fairly easy if you have a spectrum analyser, much more tricky without one.
The vocal will contain certain frequencies which will make it clear - however many other instruments are going to contain the same frequencies. If you therefore gently cut those frequencies in the other instruments, you can make the vocal clearer without the need for more volume.
With a spectrum analyser, it is just a case of looking at the frequency content of the vocal and then checking which instruments have lots of similar content, and at what frequencies, then using a graphic of parametric EQ to make the adjustments. Without out one, try and figure out which instruments are masking the vocal, and then a bit of trial and error should mean you can get it to sit better....
In the end vocal level is a matter of taste.....but it is a minefield that makes a big difference recording.... hmmmm.
And most of all, listen to your ears. They hold the secret of a good recording.
Hope this helps.
Pete
