Translation:I like to sing the National Anthem of Tanzania
I don't understand one thing:
Bendera.. ya... Taifa LA Tanzania: The flag... of... the nation of Tanzania (Taifa la tanzania is a unit that bendera relates to)
Wimbo... wa ... taifa... WA Tanzania: The flag... of... the nation... of Tanzania (Taifa..wa..tanzania is not a unit; rather, wimbo relates first to taifa, and then it relates to Tanzania)
The wa relates back to wimbo, not to Tanzania. It's not "song of the nation of Tanzania" but "Tanzanian national anthem" and "national anthem" is one unit.
[wimbo wa taifa] wa Tanzania = Tanzanian national anthem
wimbo wa [taifa la Tanzania] = song of the nation of Tanzania
The various forms of -a can, in some instances like this, indicate exactly which noun the possessive relationship refers back to.