It has been established that in the early part of the century, a band, originally called the Trehafod Recobite Band, bore the name of "Lewis Merthyr" as it received support off the then prosperous, Lewis Merthyr Colliery. In the early 1900's, it changed from an all-brass band to a military type band. Press cuttings from that period showed a regular Sunday evening attendance of thousands of listeners to concerts held in Porth Park. Lewis Merthyr has gained National Honours by winning the Third Section and Second Section finals at the National Brass Band Championships, at the then Belle Vue Manchester in 1950 & 1951 consecutively, therefore gaining "Championship" status in just three years. The band has represented Wales eight times at the National Brass Band Championships in the Royal Albert Hall, London. In 1985, having become Champion Band of Wales, the band represented the Principality at the European Brass Band Championships held at the Tivolli Gardens, Copenhagen, Denmark.

 

The band has made three recordings, two on the Pye "Top Brass" label and one on the "Look" label to celebrate its centenary in 1980.

In 1997 the band regained its Championship status, having been Welsh First Section Champions for 1995 & 1996, following the band being re-graded to First Section in 1991, following the formation of a Five Section National grading system, from the previous Four Section setup.