Friday Evenings: Slack Key Guitar Concerts. Traditional Hawaiian slack key guitar and `ukulele concerts. April 3 – Whales Homecoming; April 10 – `Ohana (Family) Slack Key; April 17 – Heart of Slack Key; April 24 – Spirit of Slack Key. Free gift drawing. Tickets: $20 ($15 keiki/seniors). Slack key guitar and `ukulele in the real old style.  All traditional music with songs and stories of the islands, telling the history of this Hawaiian musical art form. Voted 2014 Best Live Show…