Air Carrier Flight Attendants reported fumes similar to musty laundry. The fumes were mostly in the aft cabin area where flight attendants alternated time in order to spend time in the Forward Galley where the odor was less intense.

Narrative

Our C Flight Attendant (FA) had been in the back of the aircraft after service and smelled an odor! She assumed it was something in her bag and didn't say anything. Shortly after her initial smell; the B FA smelled a foul odor as I walked into the back Galley. She verbalized it and felt as if it were coming from the vents. I immediately smelled the foul odor myself; gave off moldy laundry scent. We notified the pilots at that point. We asked the A FA to come back as well to see if she could smell anything; as she hit row 32 she mention she could smell a foul odor. I made my way to the forward Galley to guard and give the pilots a break. The First Officer (FO) came out of the Cabin first and went to the aft of the aircraft to see if he could smell anything! After the FO went to the back of the Aircraft he made his way back into the Flight Deck. I called to the back after the pilots break was over and had the C and B Flight Attendants make their way to the Forward Galley so they would be removed from the area; since they had spent the most time in the Back Galley! I went back to the Galley and put all equipment away and could still smell the odor. I bent down and could smell it strongly at floor level. At that point I made my way back to the Forward Galley where I remained until descent and landing. That Flight Attendants have access to the same table the pilots have. We preach CRM and I just found out they have a table to follow that has FA assignments or duties that we don't have access to!