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Finding the right mouthpiece for your soprano can be a frustrating and daunting task. There are three main issues you're having to deal with: (1) you don't play the instrument that often, so you don't know if it's the equipment or you, (2) by design the instrument is inherently out of tune, so even when you have a great mouthpiece, you're using it to play an instrument that may be out of wack , and (3) let's face it, many of the sopranos and soprano mouthpieces are horribly made.
That being said, here are a few mouthpieces that I’ve come across that seem to get the job done: the Bari, Selmer, and Vandoren.
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Bari mouthpieces are pretty good if you’re looking for something nice and easy blowing. They are especially good if you’re looking to double. You can really push them as far as the volume. So if you’re coming to the soprano from the tenor or baritone saxophones, this might be the mouthpiece for you. They tend to get a little sharp in the higher register, but nothing a tuner and some long tones won’t take care of. The actual sound of the Bari mouthpieces, however, is somewhat built in, so it’s hard to really personalize—which is fine if you want something to get you through the gig.
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When I first began looking for a set-up to play on, I tried hard rubber and the metal Selmers of various sizes. Selmers are probably the most consistent mouthpieces I’ve played. The sound is pretty uniform from the lowest register of the horn to the highest. In some ways they are just the opposite of the Bari’s because they can be difficult to push. I eventually gave up on them because I couldn’t find one that could stand up to the kind of intensity I wanted to play at. But they worked well for Lacy and Coltrane. Another thing. If you are in an acoustic situation that doesn’t require you to blow very hard, like a sax quartet or a recording with softer sounding instruments, this could the mouthpiece of choice. But if you’re going to play a two set gig, with no mic, and a loud drummer, this may not work very well.
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I find the Vandoren to be somewhere in between the Bari and Selmer. It’s not quite as easy blowing as the Bari, which is good. If the mouthpiece is too easy blowing, it ends up calling the shots more than you. It took me a while to really learn how to project over a rhythm section, but when I did, it was more because of my ability, and less having to do with the mouthpiece. Vandoren’s also have a very dark sound, similar to the Selmer, which is good since sopranos tend to run a little on the bright and harsh side. And let me say, there’s nothing worse than hearing a lovely ballad being destroyed by a bright, loud, and harsh soprano sound. Lastly, Vandoren’s don’t sound as uniform throughout the entire register of the instrument like Selmers. But that’s OK. It’s the little imperfections that give your sound character. We want our sound to be in-tune and consistent, but we don’t want to sound like a midi file either.
Now all of the things mentioned are what worked or didn’t work for me. Everyone has a different sound that they’re hearing as well as different needs.
But at the end of the day, you have to find something that's workable and stick to it until you figure it out. Sound production on the soprano saxophone is not a linear process.