Possible Clues:

• 'It is not so festive in them, initially (6)'
• Is not in the vessel that's holy for them
• Marchers of song
• Peter, Paul and Mary
• They are not in the ship at all by the beginning of November
• They are not in the ship - they're too good for that
• Cannonized ones
• They are not wholly, by the sound of it, in the ship
• Hagiographer's subjects
• Southern NFL team