Ballads were immensely popular during the early modern period (at least in England, I can't speak for the continent). Two particular resources you might be interested in are the UCSB English Broadside Ballad Archive (which also has some recordings for those ballads which include a known tune) as well as the related Oxford collection of Ballads at the Bodleian. EBBA has nearly 8,000 ballads (and claims that's about 75% of them from the early modern period), while Oxford has 30,000 that go beyond the early modern period.

Broadsides were generally fairly cheap to print (and buy), which made them easy to distribute widely. That's part of the reason why we have so many, even if some are easily damaged.

As for topics - that was pretty wide too - some trivial, some bitingly sardonic. Some are folksy, some are drinking songs, and some are about lost loves. The previous link includes the "Discontented lover' that includes the lines: "And my Saint was from me gone, / And to Heaven she is flowne, / Which makes me to say, / I can scare live a day." and a second ballad, sung to the same tune, that starts off as a drinking song, with the second line offering that they are "drinking health to our king."

John Aubrey noted the same thing, about the same time. After ordering a meal from the innkeeper, Aubrey and his friends would walk around the room singing off the ballads until it was time to eat. The songs would be set to commonly known melodies, like Packington's Pound or Fortune My Foe and, as kadune says, they could be topical or satirical. They were sold in the markets, and the seller would likely be singing them, of course.

Aubrey's Brief Lives Oliver Lawson Dick , ed.