how about something beyond the sooo traditional clarinet concertos listed above?
here are some "important" works from the 2nd half of 20th century:
clarinet concertos of note... and notorious : not in any particular order
adviso: if you havent come to terms with works such as ther berg violin concerto or bartok string quartets, many of the works below will present great listening challenges.
hindemith (very hindemith, rarely heard, ambles along as many of this composers works do. many delightful passages, but an acquired taste. most clarinets dont have the stamina or the range of color needed to lift this work. perhaps audiences dont have the patience either! not suggesting you run out to find a recording, but it needs to be on the list.)
carter (difficult for most listeners, highly important composer, good work. will be standard rep in a generation or 2) )
corigliano (easy language, most like this work)
aho (captivating at times, rarely performed composer for american audiences)
musgrave (skip the clarinet concerto, easier than the carter , erb, or yun, but a bit boring overall. however, the work for bass clarinet and orch, autumn sonata, is an unexpected journey)
denisov (superb, one of the contemp clarinet masterpieces hands down, but not an easy listen for most. especially if you find the last 30 years of highly important "classical" eastern european music incomprehensible )
tower (easy to swallow, if you like debussy's language, this is within that context, moved up a century.)
don erb (evocative, mysterious,catty gershwinesque references in the freewheeling 3rd move, a wonderful work, rarely performed. very long. moderately difficult musical language)
adams (the concerto is called "gnarly buttons", good while dusting furniture or clipping toenails, but cant be overlooked because it is by adams. easy listening musical language)
isang yun (extremely challenging for everyone, strident to most, but a highly important composer)
aside: akin to the mozart clarinet concerto transcribed for viola (mentioned by others above) -a mistake to be sure- after all, those violists have all that hindemith stuff LOL -- there is a transcription of the beethoven violin concerto for clarinet (beethoven himself was coerced to transcribe the concerto for piano so the work would be more marketable (some things never change), i heard a performance over the car radio.i nearly caused an accident. amusing, but no cigar.
2 other superb clarinet works, solo clarinet, not concertos.
berio - sequenza IX
boulez - domaines [one of the great masterpcs of late 20th c solo clarinet works.
incidently, a few years ago, boulez added small ensemble movements to answer and musically comment on the solo clarinet sections of domaines. i heard the concert in carnegie hall with boulez and intercontemp. quite amazing. havent yet seen a recording. brings the work up to a very short list of major clarinet + ensemble works of the 21st century !
happy listening,
marc