It Sang from Beyond the Stars / Journey to the Center of the Lungfish

S2, E3: Alien intruders Sleemoth and Gloog have a new plan to take over the earth they will take a page from the 60's and stage their own "musical invasion," creating mindless hordes of screaming slaves (they've been monitoring old transmissions of Beatles concerts.) Mr. Bumpy poses as a booking agent and sends them to some of the roughest venues around (inside a live volcano, etc.). Earth is saved again! / Bumpy, Squish and Molly are swallowed by the Boy's pet lungfish. Inside they find a strange old benign sailor, the Lock Ness Monster, and every weird thing in the world except a way out. Will our heroes survive to see another episode?