Celtic music
Ritchie has also produced several CD compilations of Celtic music, and authored a volume on Celtic music for the "NPR Curious Listener's Guide" book series, published in 2005. In 2006, Ritchie launched Thistlepod, a free podcast from NPR featuring new-releases from Celtic roots. In 2013, Ritchie launched Thistle Radio, featuring the classics of Celtic music. In May 2015, Thistle Radio moved from NPR to internet based radio station SomaFM.