Harper became a regular writer of liner notes for compilations of folk, acoustic and prog-rock artists appearing on record labels including Windsong, Demon, Castle, Hux and Snapper.
During this time he published one more book, Seaside Rock (2003), a small monograph on pop music in North Down in the 60s, and co-wrote Irish Folk, Trad and Blues: A Secret History (with Trevor Hodgett, 2004[4] and 2005[5]).
Freedom & The Dream Penguin, a collection of his songs – fronted by guest vocalists including Judy Dyble, Alison O'Donnell, Janet Holmes, Paul Casey and Brian Houston – was released in 2008, credited to The Field Mouse Conspiracy.
The book was promoted with articles in fRoots and the Irish Times,[10] and by a number of live events at festivals, concerts and bookshops in Ireland in mid to late 2015, and radio sessions on BBC NI and RTE including an edition of Arena helmed by Jim Lockhart.
[11] Eyes Wide Open: True Tales of a Wishbone Ash Warrior (Jawbone Press, 2015)[12] was published with a month of the piping book in October 2015, written by guitarist/vocalist Andy Powell in close collaboration with Harper.
Harper was also involved in the reissue, including booklet essay, of another 1970 Peter Eden production, guitarist Chris Spedding's Songs Without Words (Hux, 2015), and also annotated a 4CD Wishbone Ash box Road Works (Talking Elephant, 2016) in this period.
A homage to the musical soundworlds and time period Harper chronicles most often in his writing, the album featured guest appearances from many of his recent and past collaborators – John McSherry (uilleann pipes), Chris Spedding, Andy Powell, Bert Jansch (guitars), Linley Hamilton (flugelhorn), and Duffy Power (harmonica/vocal) among others.
[13] During the first quarter of 2016, Harper focused on curating for Hux Records, as the label's 150th release, Spirits From Another Time: 1969-71 a 2-CD set of unreleased studio material by multicultural British rock band Quintessence.
Original members Phil 'Shiva' Jones and Dave 'Maha Dev' Codling contributed new parts to three tracks at studios in Leeds, UK and Woodstock, USA, and the set includes an 11,000 word essay.