Sunday Afternoons:  Slack Key Guitar Concerts.  Traditional Hawaiian slack key guitar and `ukulele concerts.  April 3 – Honoring Raymond Kane; April 10 – `Ohana Slack Key; April 17 – Poina `Ole – Never to be Forgotten; April 24 – Ahupua`a – Mountain to Sea.  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…