I'll add when writing lyrics if sounding dated is the prime concern - don't forget not to include certain "things" in any song other than one written from a looking back perspecive. Sooner or later, referring to specific things can also date a song lyric. For example, I love Jim Croce's Operator but when's the last time anyone talked to an operator on a payphone for a dime.... Point being, It's not just slang one has to consider when talking about sounding dated.
(BTW, I still love Groovin' On a Sunday Afternoon, The 69th Street Bridge Song (Feeling Groovy), and Working On A Groovy Thing. There are some great oldie slang songs. )
P.S. Jim you are AWESOME DUDE!
