English composer. Organist of St Dunstan in the West (London) 1674-99. Organist of St Michael, Cornhill (London) 1684-99. Organist of St Paul's Cathedral 1687-99. Blackwell contributed works to the ‘loose Papers’ thrown before the Old Jewry Music Club that comprise an interesting compendium of the popular part song repertory during the Commonwealth and early Restoration period.