You know, the Premier League and Champions League have them. My personal favorite is the Bundesliga's. [ame="http://www.youtube.com/watch?v=aAWjYiDvZZk&feature=related"]YouTube - Bundesliga Hymne[/ame] It's certainly not a must, but it would help. I would like it if they had an "epic" one like the BL has. Random thought, I guess.
If you have the $$$, commission John Williams to write one. Just not Philip Glass; twenty minutes of running arpeggios will make the suicide rate among USL fans go through the roof.
I think this would be a badass hymn form 1:08 - 1:35 [ame="http://www.youtube.com/watch?v=4w08Ehhee9o"]YouTube - Manowar - Battle Hymn ( DEMO ) Best Version[/ame]
Do you mean for their telecasts on FSC? I believe they already have one. Or do you mean something that would be reverently sung at the stadiums before matches in honor of Mr. Marcos? Of course the USL has that obsession with flaming soccer balls, so I would recommend ACDC's 'Big Balls'.