If you can play multiple notes at once on your clarinet, it'd be a grade 6 out of 1-6 
.
Assuming you're playing the melody notes ...
If "grade" means elementary, middle school, high school, or whatever is the UK equivalent, and assuming you've played in all grades, probably low middle school.
If "grade" means the "old style" grading of music between 1-6 for competitions in the US, with 1 being something like "Mary had a Little Lamb" and 6 being Carl Nielsen's "Concerto for Clarinet, Op. 57" (looked up on Vandoren's website for hardest clarinet pieces), I'd call this maybe a 3.
Slow pieces can be hard because you have to think about expressiveness and control over your intonation. Of course, you should also play a piece just because you like it and don't worry about how hard it's supposed to be.
Please note that if you want to play the melody line with a piano or other accompanist(s), you need to transpose the melody line.
.Assuming you're playing the melody notes ...
If "grade" means elementary, middle school, high school, or whatever is the UK equivalent, and assuming you've played in all grades, probably low middle school.
If "grade" means the "old style" grading of music between 1-6 for competitions in the US, with 1 being something like "Mary had a Little Lamb" and 6 being Carl Nielsen's "Concerto for Clarinet, Op. 57" (looked up on Vandoren's website for hardest clarinet pieces), I'd call this maybe a 3.
Slow pieces can be hard because you have to think about expressiveness and control over your intonation. Of course, you should also play a piece just because you like it and don't worry about how hard it's supposed to be.
Please note that if you want to play the melody line with a piano or other accompanist(s), you need to transpose the melody line.
You're talking about the 1st movement, right?
I made the mistake of picking it for a music festival when I was in Grade 12 and being accompanied by my friend who played all but the melody line, on piano. (I played tenor sax.) IIRC, when I transposed it, my Bb tenor was in the key of either B or F#. I just remember exactly which, but it had a lot of sharps in it.
It was wickedly hard, and I got the worst mark I ever received in a solo competition. It was about 79 or so. I just know I didn't crack 80. I remember the adjudicator noting on the form that next time I should consider choosing a piece more "suited" for saxophone.
Not long after that, I started playing rock and blues. So there Mr. Adjudicator, me thinks I took your suggestion. Thanks for helpful advice!
Oh, and in hindsight, The Moonlight Sonata got me started in my rock and blues career by teaching me how to play in sharp keys at a very early age.
I made the mistake of picking it for a music festival when I was in Grade 12 and being accompanied by my friend who played all but the melody line, on piano. (I played tenor sax.) IIRC, when I transposed it, my Bb tenor was in the key of either B or F#. I just remember exactly which, but it had a lot of sharps in it.
It was wickedly hard, and I got the worst mark I ever received in a solo competition. It was about 79 or so. I just know I didn't crack 80. I remember the adjudicator noting on the form that next time I should consider choosing a piece more "suited" for saxophone.
Not long after that, I started playing rock and blues. So there Mr. Adjudicator, me thinks I took your suggestion. Thanks for helpful advice!
Oh, and in hindsight, The Moonlight Sonata got me started in my rock and blues career by teaching me how to play in sharp keys at a very early age.