Sunday Afternoons: Slack Key Guitar Concerts. Traditional Hawaiian slack key guitar and `ukulele concerts. May 3 – Hawai`i’s Cowboy Music; May 10 –Po`ina `Ole – Never to be Forgotten; May 17 – Gifts of the Ancestors; May 24 – Traditional Hawaiian Slack Key Guitar & Ukulele; May 31 – For the Birds. Tickets: $20 ($15 keiki/seniors). The concerts are nahenahe - soft and sweet.  Slack key guitar and `ukulele in the real old style.  All traditional music with songs and…