Final answer:
There is no known song titled "P and G" by Breen that features artists Lady Gaga, Justin Bieber, Taylor Swift, or Ariana Grande as of the current knowledge cutoff. Without the correct song title or context, a definitive answer cannot be provided.
Step-by-step explanation:
The question pertains to which current or future stars sang in Breen's version of "P and G". As of my knowledge cutoff in early 2023, there is no well-known version of a song titled "P and G" that features artists such as Lady Gaga, Justin Bieber, Taylor Swift, or Ariana Grande.
It is important to have the correct title or context of the song to provide an accurate answer. In the absence of the exact information regarding the song referred to as "P and G", it would not be possible to definitively determine which artist sang in Breen's version.