This is a reasonably accurate phonetic version. Should be acceptable for singing. A couple of words of explanation are necessary. The "ch" character in Welsh is always pronounced like the "ch" sound in "loch" or "Bach" and never like the "ch" in church. There are two "th" sounds in Welsh as there are in English. They are, however, spelled differently. The "th" spelling is pronounced like the "th" in "three", and the "dd" spelling is pronounced like the "th" in "that". I have written the "dd" spelling here as "TH". The toughest sound is the infamous Welsh "ll". The simplest approximation (for singing purposes) is a "thl" sound, and I've used that here.


Bugeilio'r Gwenith Gwyn
        (Phonetic Version)

Me seeTHe vahkh'-gen yi-ahnkh fole
Uhn byou uhn ole vuh fahncy
Muhveen bigeye'-lyor gwenith gwin
Ahc ar'-athl uhn eye ved'-ee
Pahm nah thy'-ee are vuh ole
Ryou THeeTH are ole eye gil'-iTH?
Gweyeth rooyn duh weld, uh vine'-ear vahkh
Uhn lahn'-ahkh, lahn'-ahkh bye'-niTH!

Glahn'-ahkh, lahn'-ahkh weet bobe deeTH
Nye vee ahm feeTH uhn fole'-ahkh
Air mooyn uh Goor a oon'-ithe duh weTH,
Goona eem dreegahr'-eTH bahthl'-ahkh.
Cone duh ben, gwel acoo drau
Hro ee meeth law wen deer'-yon;
Gweyeth uhn duh vuhn'-wess bairt eye throw
My athl'-weTH cloe vuhng hall'-on!

Trah vo dooor uh more uhn hathlt
Ah thrah vong wathlt yn tuhv'-ee
Ah thrah vo cahl'-on uhn fuhm ron
Me vuhTH'-ahn vuhTH'-lon eetee
Duh'-wed eem'-eer gweer dahn gel
Ah hro dahn sell dahteb'-yon,
Peen eye muh-vee' nye arathl, Ann
SeeTHe or'-eye gan duh gahl'-on.