imo in terms of having singing older songs but if its a "best of all" time then imo there isnt any best times

in the context of "best music" the term can have multiple meanings depending on what kind of best and what kind of music (does it need lyrics? can it be a game/show/movie?)

in terms of every song though i prefer songs that essentially have proper context and intent to it, whether it has lyrics or not, could be a song like Lucy in the Sky with Diamonds or Viva La Vida, it could be songs like Miphas theme or Here We Are, could be an intro like from Stranger Things or Quantum Leap

this is also somewhat biased by the fact that some radios repeat a song multiple times a day while others are played less than once a week or even month just because of it being either by someone more known or that someone is overly sensitive and gets offended by almost everything so they attempt to censor what doesnt need it, like not playing the first song i mentioned because of the acronym that it makes if you use the letters i capitalized

though do to people making songs similar to eachother in more recent times due to the fact that theyve found out what their intended audience likes or dislikes older songs tend to be more different imo so listening to 100 random songs from each set of 10 years youve given itll probably be 20, 50, 60, 70 and 80 being better times on average however in terms of which has the best worst songs and which had the worst best songs and whatever itd probably be the more recent songs as recording quality is probably better and doesnt melt by being in the sun for 10 minutes and can have longer songs

overall ill still go with that there isnt really a best time other than 30 and 40 probably being not as good considering that people at war and the great depression would probably make it harder to make music but... that and someone who was literally deaf made songs better than people now who arent deaf and probably have alot better ways to record things