I recall as a kid hearing a tape with some song that went, "in the year tav-shin-ayin-gimel..." , does that ring any bells? What was supposed to be special about that year?
The song you’re thinking of is Country Yossi’s parody of In the Year 2525. (The lyrics were included in the Tishre 5773/September 2012 issue of Country Yossi Magazine.)
There’s no significance to 5773 except for the rhyme.