Have to think about this one - ideas please peeps?

I recently sent a friendship card to a friend serving aboard in the forces. He received and said that it made his blood run cold? Any suggestions on what I should put as a reply, not sure what to do? Please bear in mind I am extremely fond of him. He has also asked me to send him some tunes so he can reminisce of times we were together to chill after work! Am thinking of how to do this! Any suggestions please, bless, thanks x