The best way to find the name of a song you listened to on the radio is to go to the the Yes website, which was created for people to find what songs have played on their radio station.
One you get to the website you will find a search bar at the top left of the screen. In that search bar search for the name of the radio station that you are listening to.
Once you've searched for a radio station, it will appear on the left side if it on their website If your station appears, then click on the station. The list of songs played will then appear in the middle of the screen. The list will go back as far as 35 songs, so if you were in your car any time recently, it should be on the list somewhere.
If your radio station does not appear in the search, then the radio station unfortunately is not on the website. If this happens, your best shot at finding the name of the song is remembering a couple of lines from the song and searching for the entire thing on Google with quotation marks around the lyrics. Just about every artist and song has a lyrics page somewhere on the Internet, so search for exact words from the song can often bring up the name of the song in a Google search.