many churches continue to use metrical psalters today. for example, the reformed presbyterian church of north america (rpcna) produced psalm books based on the scots metrical psalter, with the intention of making the words more modern and the translation more accurate. these were produced in 1889 (a split-leaf brown book), 1911 (unpopular due to musical complexity), 1920 (a green book) and 1929 (also green, an expanded version of the 1920 one), 1950 (a blue book), and 1973 (a maroon one) called the book of psalms for singing. a further revision has been undertaken by the rpcna, again for the purposes of making the words more modern, and also to replace some of the more difficult-to-sing tunes, such as psalm 62b, with tunes that are easier to sing. the new edition, the book of psalms for worship, was released in 2009.