LASALLE and NAFA audition you will sure have a chance. I would
say you still have a lot of time left, you can start preparing your
portfolio from now. Be it music scores, compositions, lyrics,
videography, and other arts material you have. I have one friend,
went to LASALLE and subsequently NAFA 
In the end, drop
out from the school because of the expensive school fees.
The music & audio technology field is not very big in
Singapore, job wise, it may be slightly tougher to find a job in
Singapore. Courses that is related to music... so far, none of the
polytechnic offer course that is directed to music industry.
Remember, polytechnic is an institution that churns out students to
meet the industry demand.
So far, Mediacorp is the largest employer for audio and music
students. The other employers are smaller production houses and
media advertising companies.
