No purpose here, it's classic "audiophile". From https://mpd.readthedocs.io/en/stable/user.html#real-time-sch...

"Note There is a rumor that real-time scheduling improves audio quality. That is not true. All it does is reduce the probability of skipping (audio buffer xruns) when the computer is under heavy load."

If your audiophile playback machine is under "heavy load" then you are definitely suffering a bad case of priority inversion.