Ok. I think everyone should know that the process in studio is basically - Record -> Mixdown -> Master.
The practice in making an album is pretty much different in US and in Sg. The practice here in Sg is normally that the whole entire album is made in one studio and one engineer. But in US, bands normally record their songs in different studios, and not to mention that their recording engineers and mixing engineers are normally different person. And because of that, the basic Mastering mission is to make all those songs sound as if they were recorded in one studio, and thus, sound as an album and not compilation.
But other things such as deciding the sequence of the play list, creating dynamics between each song to give consumer a "roller-coaster" experience as one listen through the whole album, and making sure that it is up to the Red Book standard. Once again, mastering is mostly done in another mastering studio by an mastering engineer.
Overall, you can say that mastering is the process of getting the "master" ready for CD pressing factory to duplication. And this is why mastering are done in the last process.
There will be event where the mastering engineer will send a mix back to the mixing engineer to do certain changes to the mix of the song if the mix is either overly-done, or poorly done. Experienced mixing engineer will know what to give the mastering engineer. From this, you should be aware that mastering is mostly done after the song is being mixed down to stereo. Individual instruments mixing are done in the mixing stage rather than the mastering stage.
And there is a big mis-conception by many pple that mastering can make a poorly-mixed song into a "wow". And there is also a big mis-conception by many pple that mixing can make a poorly-recorded material into "wow". Hence, we always emphasize that the recording stage is the most crucial stage.
So if mastering is bascially to make all those songs sound as if they were recorded in one studios, and thus, sound as an album and not compilation, well, then here in Sg, due to the small market, recording, mixing, and mastering are mostly done by one studio and by one person or two, mastering is seldom needed, or you can say that mastering is already done during the process of recording and mixing. Hence, you don't really see a mastering studio here specially doing mastering only.
For your problem Cheez, arranger normally knows some basic principals in mixing. And in Sg, most composers and arrangers are sound engineers themselves. But still, the engineers are mostly the ones doing the mixing. If the sound engineer that you are referring to is the mastering engineer, then he is probably saying that something is wrong with your mix, either overly-done, or poorly done. But however, if the sound engineer that you are referring to is doing the mixing, then it would be good that you give him all the separate audio files of each individual instruments without too much EQ-ing and etc..
If your arrangement is done in MIDI sequences, then you probably got to record each track into audio files for him import into DAW to mix.
Alternatively, if you have a notebook with an audio interface that supports multi-track digital I/O, then you can simply bring your session over to his studio and record your arrangement into his DAW via the multi-track digital I/O.
P.S. if your composition is meant for local TV programs, then the composer/arranger usually mixdown the music themselves. Scoring and Mixing for albums and scoring & mixing for motion pictures are different. Try to leave "rooms" for dialog and SFX when scoring & mixing for motion picture. But if it's meant for featured film, then usually the music engineer will do the mixdown.
