When i turn off my iphone 4 it won't turn back on?

When i turn off my iphone 4 it won't turn back on, like it'll show that apple sign until i plug it into the charger, people tell me i should restore my phone but will it delete all my pictures and music?

It may be in DFSU mode where you held the home button on power up hold them both again for 5 seconds then let go of the home button - it worked on my ipod touch 2 may be differnt now

Your phone should be backed up to your iTunes on computer but plug it in and re back it before and save your pictures on your computer before you factory reset it. Just in case.