Sunday Afternoons: Slack Key Guitar Concerts. Traditional Hawaiian slack key guitar and `ukulele concerts. June 1 – Mountain to Sea; June 8 – Poina `Ole – Never to be Forgotten; June 15 – Tour of the Islands; June 22 – Hanalei Slack Key Guitar & Ukulele; June 29: Legends of Slack Key Guitar & Ukulele. 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…