Natural Force

Natural Force is the second studio album by Welsh singer Bonnie Tyler, released in May 1978 by RCA Records. The album was issued in the United States under the title of It's a Heartache, with alternate cover art. As with her debut, Ronnie Scott and Steve Wolfe wrote most of the tracks on the album. David Mackay again produced the album, with Scott and Wolfe. Other songs include covers of American artists Stevie Wonder and Carole King.

Five singles were released from Natural Force. The second single, "It's a Heartache", is among the best-selling singles of all time, with sales of over 6 million copies. It became Tyler's first charting single in the United States, where it was certified gold by the Recording Industry Association of America (RIAA). Many other singles from Natural Force also fared well in Europe.

Natural Force became Tyler's most successful album for RCA. In the United States, it reached number 2 on the Top Country Albums chart, and number 16 on the Billboard 200. The album was also a success in Europe, but like its predecessor, it failed to chart in the United Kingdom.