As one might guess from their name — which is pronounced “krungbin” and means “engine fly” in Thai — Houston-based trio Khruangbin is not intentionally aimed at the pop market. With stated influences like East Asian surf-rock, psychedelia, West African and, of course, Thai music, the group’s sound pits Mark Speer’s deceptively complex guitar work over the steady pulse of bassist Laura Lee Ochoa and drummer Donald Johnson. And despite those seemingly challenging elements, Khruangbin’s music is so melodic — and just plain good — that they’ve become popular beyond even their wildest hopes, as stated in a recent New York Times profile.

Apart from a tag-team EP with R&B singer Leon Bridges last year, the group’s past work is almost entirely instrumental — but for “Mordechai,” their third full-length, they’ve added vocals to nearly every song. While the album contains some of their best songwriting to date, the results are mixed — the vocals, mostly by Ochoa, simply aren’t up to the group’s formidable musicianship and, in a couple of cases, particularly the funked-up “Time (You and I),” can make one wish the songs were instrumental.

However, on most songs, Speer’s inventive guitar playing remains the focal point. An unusually melodic player, his guitar work is clearly influenced by West African, Caribbean and Asian music, but for rock fans it’s also reminiscent of vintage Johnny Marr, even though Khruangbin sounds absolutely nothing like the Smiths. Like Marr, he shifts deftly between simple, memorable lines and complicated arpeggios with lots of notes. On this album, “Father Bird, Mother Bird” and the haunting closer “Shida” find him unspooling gorgeous, elaborate, cascading melodies.

And on several songs, the vocals work — “Pelota” features Ochoa singing in a traditional Spanish style; on “One to Remember” she essentially sings a distant harmony with the stunning guitar work; and “So We Won’t Forget” finds all of the elements coalescing, with the vocals acting as a counterpart to what may be Speer’s best melody to date, a jaunty, African-inspired figure.

Be all of that as it may, the trio’s instincts have not failed them yet, and “Mordechai” contains this unusual and alluring group’s best work yet.