Apple Music: Does turning off the Sync Library Setting Delete all of my songs?

Hello,

I recently Synced my library when I activated my free Apple Music Subscription trial. However I initially downloaded my songs in my library locally long before I had the Apple Music Subscription. My question is that if I turn off Sync Library via Settings > Music > toggle Sync library off, will it delete all of my songs and playlists including those I downloaded locally long before I had my subscription, or just songs I downloaded during my subscription?

thanks for clarifying!