Disco con Tutti by Kevin MacLeod is licensed under a Creative Commons Attribution license (creativecommon...) Source: incompetech.com... Artist: incompetech.com/
Loud mastering is the use of limiting and compression on the master, so it has nothing to do with the recording level. As you are recording a -21db, and as 6db equal 1 bit, you are effectively recording at 13,5 bits instead of 16 (which is the format you chose). In general, you should aim for the highest possible recording level.