Loose means many things until you describe the surfaces.
Basically blades are loose to permit easy assembly in a cascade fashion without stack up of tolerances causing interference.
They become extremely tight in their attachments as soon as they start spinning. In spite of this they can still move imperceptively against their atttachments in order to dampen out vibrations that might cause fatigue.
The noise that you may hear when hand turning a rotor full of blades is typically due to the blade rocking in its slot at very low speed.
When you start adding things to the blade like dampners, snubbers, shrouds etc. you have to be very careful not to interfere with the set of the blade at full speed and temperature, thus these devices often create tinkling noises, when present, when turning the rotor by hand.