If it were me, I'd check out COMPASS' criteria for joining as publisher member (
http://www.compass.org.sg/UserFiles/File/Publisher Application_Rev 1.pdf).
I'd also thoroughly read the COMPASS site and other music intellectual property sites to distinguish between the 3 different sets of rights (sound recordings, publishing (ie reproduction) and public performance). I'd also read Danelectrico's first post on Soft to get a good summary of that.
http://soft.com.sg/forum/music-kopi-tiam/16141-copyright-issues-post259396.html#post259396
I'd then write a bunch of songs (at least 5 - to meet COMPASS' criteria) and register my own sole proprietorship publishing business. I'd proceed to have them commercially recorded (either on my own or through friends or through working with other local bands) and distributed by a record label, major or indie, in a way that meets the "commercial distribution" criteria of COMPASS. Hey, if other people don't wanna use your songs, chances are they're not really good to begin with. Once these are commercially released, I'd join COMPASS as a publisher with regard to my publishing business, and songwriter in my individual capacity - for the collection of public performance royalties. Hopefully I'd get at least a couple radio or commercial "hits" out of these songs and start building up a name and reputation within the industry. In the meantime, i'd be collecting some nice royalties from the modest commercial success of my first endeavours.
Once that happens, I'd at least have a portfolio with some proof of my songwriting / hitmaking ability. I'd leverage on my COMPASS contacts or other burgeoning industry contacts to fix up meetings with the other bigger publishers who will be registered with COMPASS (this means the big 4 companies) and try to pitch a sub-publishing deal with one of them (ie leverage on their network of contacts) and try to negotiate for an advance in the deal. If it works out right, I'd have ended with a 75 25 deal, a 10k advance (which means they're gonna do their darndest to make it back - incentive for them to push my music!), and a foot in the door of the big time industry players.
Why does this sound so complicated? Because there's no free lunch and without these, few if any major publishers would give you time of day if you're shopping an untested and untried demo to them. They have thousands of writers much higher in priority that they're trying to earn from. Why would they care about an upstart with no track record. And if they do give you a deal, it'll be one on crap terms as their bargaining power would be much stronger - forget an advance, you'd get the bog standard 50 50 split and you'd be of such low priority in their stable that it'd be a miracle if they manage to shop your song to any artiste who'd actually want to use it.
Really, good luck - it's a tough road and you're gonna need it.