The query appears to be related to a specific music platform or a request to design a feature for one (likely Webmusic.in
A: No. All free download sites offering copyrighted Hindi MP3s are illegal. The only legal free music is from platforms like Free Music Archive (but very little Hindi content). webmusicin+hindi+a+to+z+mp3+song+exclusive
If you manage a large local MP3 collection, consider using advanced players like foobar2000 The query appears to be related to a