The topic of work visa was previously discussed. Having a university degree is irrelevant to your eligibility for a work visa, what important is that your work skills stands out and what you are able to offer are considered to be talents thats not available in Japan. A good start for info is here:
Japan Visa,Japanese Embassy Requirements,Work,Travel Visa Application Form,Tourist,Holiday,Student,immigration information
Your current citizenship is also irrelevant, all countries associate a risk factor to applicants base on their citizenship, in your case, you are probably low risk to anyone since Singapore is not known to be associated with any terror activities
Standard of living is high comparing to other Asian countries. With living and transportation cost being the highest.
I am not familiar with the music/entertainment industry in Japan. Maybe someone can comment on this.
User MMM and Nagoyayankee usually have lots of info to offer as well, please look for their other posts