Simplify the following text for a Grade 10 native English-speaking person.
Original: The Cathedral Choir is supported financially by the St Olave 's & St Saviour 's Schools Foundation , which stems from the two parochial schools set up in the 1560s which still hold their commemoration and annual services here as their ` foundation ' church .
Simplified: The cathedral has three choirs , The main Cathedral Choir is supported financially by the St Olave 's & St Saviour 's Schools Foundation . They were two parochial schools set up in the 1560s , and still hold their annual services here as their ` foundation ' church .