Final answer:
The question lacks context to identify the #1 song on the charts; specific details such as time period, location, or radio station are necessary for an accurate response.
Step-by-step explanation:
The question asked does not provide enough context to determine the name of the first song heard on the radio or the #1 song on the charts. To answer such a question, one would need specific details about the time period, location, or particular radio station referenced. Music charts can vary by country, music genre, and date, so the #1 song on the charts can only be identified with additional context. Furthermore, if the question pertains to a specific narrative or fictional scenario, even more context would be required to provide an accurate response.