Kaprekar’s Constant,”Depth of Field” (Talking Elephant)-The eagerly anticipated follow up to the highly accomplished prog rockers’ 2017 debut set, “Fate Outsmarts Desire,” is the first to feature former Caravan drummer Mark Walker and also boasts telling contributions from saxist David Jackson of Van der Graaf Generator fame and Jethro Tull frontman Ian Anderson.The musical content strikes an appealing blend between epic narratives such as “White Star’s Sunrise” and “Rosherville” and shorter pieces such as the elegantly tuneful,”The Nightwatchman,” capturing the pastoral essence of Kaprekar’s Constant’s archetypally English brand of music making in the process.