The term 'Palindromic Pop Quartet' refers to the Swedish band ABBA, which is known for their hit songs and palindromic name. ABBA was formed in 1972 and quickly rose to international fame with their catchy pop songs. They are one of the most successful musical groups of all time, selling over 400 million records worldwide. Their name is a palindrome, meaning it reads the same forwards and backwards. ABBA's music has been featured in numerous films, television shows, and musicals, and their songs continue to be popular today.