There is a shortcut to access the iPod control without unlocking the lock screen. You can simply double click the home button and iPhone shows up a simplified version of iPod control, so that you can pause or skip songs. For detailed checkout the tips here.

GlovePod, a tweak available from cydia, offers even better control for music playback on iPhone. By installing the hack on jailbroken iPhone, it allows you to pause or skip songs through the volume and sleep buttons.

Install GlovePod Via Cydia

Launch Cydia > Select “Sections” at haptic menu > Select “Tweaks” category > and select “GlovePod” or you can tap “Search” in Cydia and type “GlovePod” > Select “install” button at the right top and confirm it to install.

After double-tapping the home button to invoke the iPod control, you can now press the volume buttons to change songs. The hack turns volume up/down buttons into forward/backward buttons respectively. To pause the music, press the sleep button and hold for a couple of second. You can press and hold the sleep button (again for one to two seconds) to resume the playback. It intends to let you control music playback on iPhone while you’re wearing gloves in winter.

GlovePod is now available on Cydia for free. This tweak will be effective after rebooting your iPhone.