Looks like you couldn't figure out if you wanted to spell it "disc" or "disk" (you have a lot of inconsistent back-and-forth in your post!).
You can do an Aggregate Query where you group on the DiscID fields and just take the First of all the other fields.
Code:
SELECT
First(DiscContents.disc_contents_id) AS FirstOfdisc_contents_id,
First(DiscContents.composition_id) AS FirstOfcomposition_id,
DiscContents.disc_id,
Discs.DiscID,
First(Discs.miscellaneous_text_fields) AS FirstOfmiscellaneous_text_fields
FROM DiscContents
INNER JOIN Discs ON DiscContents.disc_id = Discs.DiscID
GROUP BY
DiscContents.disc_id,
Discs.DiscID;
Note that you CANNOT use "*" on Aggregate Queries, you need to list out every field you want to display.