yes you can go thru with this BLOB type a sample apps is here http://www.php-mysql-tutorial.com/wikis/mysql-tutorials/uploading-files-to-mysql-database.aspx ( simple google search gives that )
sure you can BLOB type field is made for this reason...you can store anything in your database... some peoples think that storing images or vids in a server as files is best than storing them in a databas..but thy are wrong
Don't do it you will BLOB down your database speed. Unless you want your database to be almost impossible to backup and restore go ahead
You can store any type of format in database but you can store it in binary format while fetching you cannot give download directly to the clients specially on web
If you store images or sound files in database it will slow your db and probably get corrupted.Upload your big files,(music,images) into your directory,store the path in your db, and use that path in retrieving them.