If you ask a jazz guitarist who they study, a few names come up constantly, and Toninho Horta is one of them. Not because he's famous in the way Wes Montgomery or Jim Hall are famous, but because he figured out a harmonic language nobody else uses quite the same way — open strings ringing under moving chords, voicings that feel like they shouldn't work on a guitar but do. He's from Belo Horizonte, a city that produced its own strange and beautiful pocket of Brazilian music in the late 1960s and 70s, centered around Milton Nascimento and a loose circle of songwriters including Lô Borges. That scene got nicknamed Clube da Esquina — the corner club — and Horta was one of its quiet architects, writing songs and arranging guitar parts that gave the whole thing its floating, unresolved quality.

What makes his playing distinctive is hard to pin down without a guitar in your hands. He tunes the instrument in ways that open up clusters of notes a standard tuning won't give you, and he writes melodies that slide through those clusters instead of sitting on top of them. It's not flashy guitar playing. There's no shredding, no look-at-me technique. It's composer's guitar — every note seems to be there because it has to be, not because it sounds impressive. That's part of why so many jazz musicians who've crossed paths with Brazilian music end up citing him as someone who changed how they thought about harmony on the instrument.

His own records as a leader took a while to catch on outside Brazil. Terra dos Pássaros (1980) is a good entry point — it's got the open-tuned guitar work front and center along with his singing, which is warm and unforced, never trying to be a showcase voice. Later he made records aimed more squarely at the American jazz audience, mixing in horns and a more polished studio sound, which won him new listeners even if some of the earlier records have more of that unguarded, homemade Minas Gerais feeling.

He's spent a career as a connector more than a star — writing songs that other singers made famous, showing up on other people's albums, teaching guitarists things they couldn't find anywhere else. If you want to understand why Brazilian harmony fascinates jazz musicians the way it does, spend time with Toninho Horta's records before you spend time with anyone else's analysis of them. The guitar explains it better than words can.