Don't give up!

I'm in the middle of preparing a school assembly on prayer, but it seems that God has a message for me & St Peter's church. The passage is Luke 18:1-8, and Luke leaves us in no doubt as to the meaning of the parable:

Jesus told them a parable to the effect that they ought always to pray and not lose heart.

The application? Well, yes to prayer in general, but perhaps more specifically to our prayers that God would send us a musician. We've been praying along these lines for several months, and so far there's been no positive answer. But 'don't give up' is the message, 'keep praying, keep asking; individually and together, persevere in prayer.'