enjoy, amuse, please, joy
悰 centers on a lighthearted, positive emotional state: feeling joy, being amused, or taking pleasure in something. The given meanings all describe enjoying oneself or pleasing others.
悰 combines the heart radical 忄 with 宗, which likely provides the sound. The exact historical development is uncertain, but the structure suggests a phono-semantic compound where the heart radical points to an emotional state.
The heart radical 忄 beside 宗: picture a joyful heart at a festive religious gathering, where everyone is amused and pleased.
For ソウ, imagine a soulful song that fills your heart with joy: soul -> ソウ, and the music amuses everyone.