you have to learn popular songs off the radio by ear - maybe grabbing a cassette. By the time they consider publishing them (if at all), they are old news and off the charts.
Public performance, BTW is compensated at the venue level by ASCAP or BMI memberships.
The venue owners are expected (threatened) to join one of these publishing orgs and their membership money is distributed among the songwriters. So its not like they're not getting paid at all. They just want another income stream I think.
I remain adamant that only paid performances are worthy of compensation and use of charts for study and personal pleasure ought to be free. Performances include mechanical performances (playing a CD) in a place of business (like a coffee house).
Good artists copy, great artists steal. All artists are outlaws it seems. Well - so be it.