The song that sold the most ringtones can vary depending on the time period and market. Different songs may have held this title at different points in time due to changing trends and consumer preferences. It’s challenging to determine a single song that sold the most ringtones without specific time and location parameters.

As of September 2021, the iPhone 13 had not been released, so there was no specific ringtone associated with it. Apple typically includes a default ringtone with each new iPhone model, but the specific ringtone for the iPhone 13 would not be known until its release.

The most heard or popular song can also vary depending on various factors, such as region, music charts, streaming platforms, and personal preferences. It’s challenging to determine a universally most heard song as it can change over time and across different demographics.

The number one listened-to song would depend on the specific context you’re referring to, such as a particular music chart, streaming platform, or a specific time period. Without additional details, it’s not possible to provide an accurate answer.