Those seeking mystic perfections are motivated by their desire to control matter, subtle and gross. Those who are sincerely interested in spiritual life should try their best to become free from such material desires. I have seen many people who belong to lines that focus on siddhis. Some of the siddhis are amazing, some are just stupid. Through various processes of meditation one's mind is expanded and the understandings of matter become much greater.
All matter is based on sound, so through sound it can be manipulated.
Furthermore, the physical realm of our experience exists and is based on the subtle mental realm. Those who have conscious access to that realm can know and do things that we would consider to be mystical or supernatural. There are eight primary siddhis described in the scriptures, and ten secondary perfections. The ability to decrease the size of one's body and become smaller than the smallest particle. Through this siddhi one may enter into stone or change the density in one's body, enabling one to pass through solid matter.