Belgian band Waterloo's only album, First Battle, was originally released in February of 1970, a crucial time of transition for European rock; this was the tipping point where the expansive sounds of psychedelia lost some of their trippiness and began moving toward a technically complex progressive rock style. Though King Crimson and Yes had released their first albums by this time, prog was still very much in its infancy, and First Battle falls squarely under the proto-prog umbrella, retaining trace elements of psychedelia but definitively leaning into a more sophisticated, classical-influenced realm. One of Waterloo's key inspirations was the Nice -- a proto-prog outfit if ever there was one -- and the influence of both the Nice's Keith Emerson and the contemporaneous sounds of Deep Purple's Jon Lord can be heard in the fleet-fingered Bach-goes-beard-rock licks of organist Mark Malyster. Malyster's riffs share the spotlight here with Gus Roan's guitar work, which, in a manner typical for early prog, often sounds a bit more earthbound and blues-based than the keyboards. The top end of Waterloo's musical mix is completed by singer Dirk Bogart's flute playing, which can't help but put listeners in mind of Benefit-era Jethro Tull. As First Battle was merely a tentative step on prog's road to excess, most of the songs are short and to the point, maintaining a kind of muscular, Move-like psych-pop sensibility, the lone exception being the 11-minute "Diary of an Old Man," with it's bluesy/jazzy jams. The bonus cuts are another story, though -- some of them feature the band's second (post-album) lineup, which included saxophonist John Van Rymenant and moved toward a more intense, jazz-tinged style for a couple of singles. Shortly after these later releases, Waterloo disintegrated, with a number of members forming jazz/rock band Pazop.