Complex sentence: From 8 November 1958, a Top 10 album chart was compiled by "Melody Maker"; although the "Mirror" chart continued to run after this date, "Melody Maker" is taken as the canonical source as it had a larger sample.
Split into simpler sentences: From 8 November 1958, a Top 10 album chart was compiled by "Melody Maker". Although the "Record Mirror" chart continued to run after this date, "Melody Maker" is taken as the canonical source as it had a larger sample.