Music
Dad was a wonderful musician. He started piano lessons at a young age (exact details are outlined in education). He played the organ at church for many years. A few noted items:
At church, our family would sit in the front row right near the organ, so that dad would have easy access as he needed to be up and down somewhat frequently to play. However, in a family of 6 kids, mom alone on the bench was often not enough. Consequently, the children would frequently march up to the organ (while dad was playing) and ask him about something we wanted that mom was too busy to take care of. He would easily keep playing the organ and turn to face us and talk to us about whatever we needed. This talent was not missed on the rest of the congregation, as I recall several times in my youth having other members of the congregation remark how amazing it was he could talk to us and play at the same time.
He was also very well known for being able to play Chopin's "Waltz in D Flat Major", opus 64, No. 1 - commonly called "The Minute Waltz" in exactly one minute, without a metronome. I recall him actually doing this at a ward talent show one time. Marjean was sitting near the front, and as soon as he finished, she jumped up and hollared "Exactly one minute!" and held up her watch. She had timed it. Dad used to play the piano late into the night at our home - I recall falling asleep to his playing as a little boy.
During my highschool years, dad was the choir director at church. He did a wonderful job picking out pieces for us to sing, and helping the choir do the best job they could. I recall sitting next to Steve Johnson and helping him learn how to read the music for the tenor and bass parts that we were singing.
Stamp Collecting
Dad collected stamps in large quantities - he would buy sheets of new issue stamps at the post office, and collect stamps from mail he received. He especially loved to collect foreign stamps. His collection was not particularly valuable, but rather served as a simple pastime for him.
Cameron has more information on this.
Coin Collecting
He collected coins as well. I recall as a young boy he would like to see my nickels whenever we were out shopping together and I received change. He wanted to see if I ever got a buffalo head nickel. His coin collection was large like his stamp collection, but did not contain anything particularly valuable. Reed has more information on this.