Sunday Afternoons: Slack Key Guitar Concerts.  Traditional Hawaiian slack key guitar and `ukulele concerts.  August 4 – Honoring Raymond Kane; August 11 – Hawai`i’s Sunset Music; August 18 – Spirit of Slack Key; August 25 – Hawai`i’s Cowboy Music – Slack Key Guitar.  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 stories of the islands, telling the history of this Hawaiian…