Complex sentence: Another rival publication, "Melody Maker", began compiling its own chart and telephoned 19 stores to produce a Top 20 for 7 April 1956; it was also the first chart to include Northern Ireland in its sample.
Split into simpler sentences: Another rival publication, "Melody Maker", began compiling its own chart; it telephoned 19 stores to produce a Top 20 for 7 April 1956. It was also the first chart to include Northern Ireland in its sample.