I have first generation iPad. Sound plays for iTunes, Garage Band and for internet (You Tube, etc.). The sound does not play for other apps that require sound such as games, other musical apps. This problem just started happening recently. I have reinstalled apps. I have resynced the iPad. Nothing has helped. All of the settings have the speakers set up. Any ideas?
Have you got notifications muted ? Only notifications (including games) get muted, so the Music and Videos apps, and headphones, still get sound.
Depending on what you've got Settings > General > Use Side Switch To set to (mute or rotation lock), then you can mute notifications by the switch on the right hand side of the iPad above the volume switch, or via the taskbar : double-click the home button; slide from the left; and it's the icon far left; press home again to exit the taskbar. The function that isn't on the side switch is set via the taskbar instead : http://support.apple.com/kb/HT4085