Mid- to late-20th-century music written for woodwind doublers, such as musical theater “books,” largely solidified around three main types of doubling specialists. The most common of these is the clarinet/saxophone/flute player. Less common but still widely used are the oboist with passable single reed skills, and the “low reeds” bassoon/bass clarinet/baritone saxophone player.
In the 21st century, “doubler” woodwind sections have shown a tendency to shrink in number of players while growing in number of instruments. That means that some new combinations of instrument are becoming common that weren’t before: for example, it would have been very unusual in the late 20th century to write both flute and oboe into the same book, but this is becoming much more commonplace.

My sense is that woodwind doublers today are more willing/likely to embrace double reed playing, despite those instruments’ reputation (deserved or not) for being more difficult and their reputation (deserved) for being more expensive. But there seems to be some emerging conventional “wisdom” that oboe or bassoon is the way to go, and that playing both is inadvisable. I have to disagree.
It seems unlikely to me that the trend of shrinking woodwind sections, with increasing demands on individual players, is going to reverse. I predict that within a decade or two we’ll see movement in major Broadway productions toward doublers playing oboe and bassoon in the same book.
There’s another wrinkle to this: not all doublers are making their living in top-tier performance situations. It’s quite common for a small- to medium-sized university, or a large high school to hire one person to teach “double reeds.” Nearly always, this means hiring someone who is well-qualified on oboe or bassoon and relatively clueless on the other. I think oboists or bassoonists headed for doctoral degrees and university teaching would be well-advised to consider getting a minor, or at least some lessons, in the other double reed. (There may even be room for someone to develop a graduate program in “double reeds,” or perhaps at least the ability to tailor an existing multiple woodwinds degree to accommodate this.)
Woodwind doublers already understand the benefits of being able to get the doubling gig, but also to get a broader array of single-instrument gigs. If you have the motivation to pursue both oboe and bassoon, I think you will find—as I have—more opportunities to make music.
I studied clarinet in college with Caroline Hartig. She had a great way of explaining/demonstrating voicing on the clarinet.
With the mouth open, teeth slightly apart, you make a really intense and forceful “SHHH!” sound. It really puts the tongue in a great position for making a nice clarinet sound.
I have had a number beginning students whose clarinet is so loose in their mouths that it will actually move around while playing or when they are attempting to tongue. Many end up playing 1/4 to 1/2 tone flat. Firming the embouchure is exactly what they need. While I would not encourage any student to bite, sometimes greater embouchure support is exactly the fix that is needed.
I have to disagree with you on this. “Firming” or “embouchure support” is tightening, and might raise the pitch but has negative effects on tone, response, and dynamic range. The flatness problem you’re describing is a classic voicing issue. The clarinet moving around during articulation is a tongue movement problem, and/or failure to bring the upper teeth in contact with the mouthpiece beak.
Voicing is harder to teach than “tighten (or ‘firm’) your embouchure,” but well worth it for the superior results.
I agree…first thought when I read the above comment was that the upper teeth are not in contact with the mouthpiece. I do the wiggle jiggle test and go from there. I’m not sure if this is the best thing but I tell them if they are doing it correctly they will eventually see teeth marks on their mp or teeth cushion.