Apple was recently granted a patent for a new proprietary technology that would allow them to automatically censor audio content. The technology would allow them to identify specific words and pick them out of the audio as it is being played or broadcast; it also has the ability to separate the music and lyrics, potentially just drowning out the unwanted content.
The patent was actually filed in the second half of 2014, but was only granted recently. It is not exclusive to music, and could be applied to literature (audio books), as well.
How this technology will be used, or whether it will end up being used at all, remains to be seen. This could be a way for Apple Music to be more “family friendly,” as Consequence of Sound put it. It could also be used in conjunction with a sort of parental lock on explicit content.