[1] There is the saying that is well-known and often advised, “If you can imagine doing anything other than music for a living, do that.”
[2] Then there is the idea of having a Plan B.
If there exists a Plan B that is something other than music, does the standard wisdom [1] say to discard the musical career immediately?
Just let things happen. There are lots of ways to do music: it can be a total focus, half of a dual focus, or part of a tapestry of many interests. If a high school student develops other interests, that is very healthy, but does not mean music has to be discarded.
When the time comes, your son can read this : http://www.peabody.jhu.edu/conservatory/admissions/tips/doubledegree.html and figure out where he falls 
I don’t think “Plans” help at this point, and may even hinder. Waiting to plan is tough in music, because of the time and energy involved at an earlier age, but if he stays flexible and follows his inclinations, things will become clear.
By the time plan B kicks in your student will be an adult. It’s their life. Let them figure it out.
Agree with the above posters. Life happens despite our “best laid plans”. You adjust.
I don’t happen to agree with [1]. I’m sure my son could see himself doing something other than music, though I don’t think he can imagine not doing music (if that makes any sense.) It’s clear though that music brings him joy. And on a very pragmatic but very key point, he can practice hours on end, everyday, and find deep satisfaction in it.
As for “plan B”, I think it also depends on what you think “music” encompasses. If you’re a purist and consider it to be just performing artists and perhaps composers, then there are a lot of music-related careers out there that might fall under “Plan B”. We were at Berklee this past weekend and it seemed like every student we met was double-majoring or minoring in some sort of a music industry professional program, such as music production/engineering, music business management, music therapy, etc. This is probably more prevalent for non-classical musicians.
@ScreenName48105 - ah! I was posting as more of a logic puzzle than as an issue-at-hand, as you saw. I hadn’t seen [1] explicitly challenged before.
A funny thing happens after undergrad…you stop feeling ownership towards your kid’s career (maybe it happens earlier or later for others). I struggled in her high school and early undergrad days to answer the old “so what’s she going to do with that degree” - feeling somehow responsible. Now I just say, “I don’t know. It’s her business not mine.”
Plan B? That was for me … not her. So was the first question. These are things adults ask. While our kids continue on their merry way.
“Plan B” is important for the short-term. For example, what if you are not accepted into any programs for next year? You should have a plan in place for what-if. But for the long run, it’s hard to make a detailed plan because so much is unpredictable.
I knew my S could never imagine living life without composing when in high school he was walking home and didn’t have pen or paper but had to write down a musical phrase - he dipped a stick into a fallen plum and wrote on a leaf! That’s when I knew his path wasn’t a choice but an essential.
It gets tricky, and this is one of those things that can engender a lot of ‘spirited’ discussion. I think there is truth to the statement, it is one thing to have doubts about a chosen path, but that if you plan on going into music you need to have the kind of passion where you are willing to put in the work, which can be so time consuming and grinding, starting even in high school and before. The problem with the plan B, of seeing other things, is that you may not have the focus and drive in terms of music to actually have a chance of making it as a musician. That doesn’t mean if you decide to go into music performance and then find it doesn’t work you are heading for disaster, what that means is if you seriously see yourself in a life of music as a professional, if that is your driving passion, that actively working on ‘plan B’ might be a self fulfilling prophesy towards making plan B happen. That doesn’t mean a student shouldn’t think of plan B, and the one thing about a performance degree is that it does leave a lot of doors open, it is a college degree that is respected both in the ‘real world’ and if you choose to get a grad degree in something else, I am just saying that if you let the plan B become a major focus it may end up sabotaging the goal of getting into music performance.
Keep in mind that I am talking about so called ‘classical’ music, which in many ways has its own unique world and protocols (much of which, quite frankly, I am ambivalent about), and it can be different in other worlds, and it is also different for every music student. There are kids, for example, who do high level music in high school and also do the academic superstar stuff, have the 8 aps, all the ec’s, the 4.0, etc, etc, but that also isn’t that common IME, and there are kids who do dual degrees who come out as incredible musicians with also an academic degree, but there are also a lot of kids who go the dual degree route who either drop the academic degree, because they find their music is suffering, or they drop music, it is a minority of dual degree kids IME who come out at the top of their game musically (and keep in mind this is strictly what I have seen and heard, I claim no universality) and a lot of those who continue with the dual degree often end up not quite at the top of their game musically.
It isn’t that with ‘making it in music’ means only being a full time musician, but rather that I feel if that is your goal (to be full time as a musician), that music needs to be a passion where that is all you see yourself wanting to do among a pool of things you might want to do. It could be that if you already see music as something you would do with other things, then for example a dual degree in computer science and a BM might work out great where the person would end up working a computer job and would be doing music on the side, either as an amateur or semi pro doing gig work, and where the level of playing ability wouldn’t need to be at the level required to do it full time (for example, trying to get into a major full time orchestra or into a full time chamber group).
Okay I see, it’s a logic problem. But as someone else said, the #1 is faulty. Plenty of people who do music can picture themselves doing something else. They just want to do music, for now anyway.
And having a Plan B (equivalent to being able to picture oneself doing something else, is that the idea?) doesn’t mean you have to discard music. Otherwise that other thing would be Plan A 
You have received many good answers. For our son saying he had a “Plan B” was sabotage. He felt/feels if he is going to devote himself to music he needs to devote himself to it. When we sent him off to conservatory we had this fantasy that our bright boy would cross register at Harvard or Tufts and transfer once he realized he needed more intellectually. Instead our son has completely devoted himself to music and treats his intellectual curiosity as a hobby, reading books that many of his peers might read for a college literature or history class on his own. He has not cross registered for a single liberal arts class.
I agree now that he is about to graduate, it is his life not ours. He has to figure out how to make next year work. And trust me he is thinking about it all the time. It isn’t easy but then it is only those who are willing to do the hard work and make the commitment and sacrifice to have a music career that ever make it. I somehow think he is going to sort it out. One thing he has that we as parents do not have is regular contact with working musicians (recent alumni, faculty, DMA students etc…) As a young adult who is about to turn 22 he knows what the obstacles are.
Meanwhile when he started at his conservatory there was another boy who studied with the same teacher in high school. This boy was also quite bright and obviously talented enough to get admitted. That boy spent one year at conservatory and then decided he did not want to spend all his time only doing music and he transferred to a small liberal arts school. Kids learn and change and I suppose that is their own plan B.
My daughter started college at a conservatory theater program. She was convinced that she wanted to work in theater and was passionate about it. But after a year she found herself wanting to take psychology classes. She transferred two times after that, each time her major shifted until eventually she realized she wanted to be a health care provider rather than just act like a health care provider. She is now a Nurse Practitioner. Some might say her time was wasted doing theater for a year. But I can tell you that when she was getting her degree and being evaluated on her clinical skills she always got extremely high scores and praise. She did some clinical work in a woman’s prison and I can tell you all those acting skills and the study of body language came in handy.
Let your child be your guide with this and try not to influence him/her too much with your own biases and he/she will land in a great place.
I didn’t know where this topic would go, but it looks like it can no longer be a blanket statement on CC to say [1] “If you can imagine doing anything other than music for a living, do that.”
The new statement, [3] “Feel free to pursue music for a living until you decide to do something else” is very compatible with the idea of a Plan B.
I think we also have the option to say, [4] “If you can’t imagine doing something else for a living, don’t worry about an absence of investing in Plan B.”
Thanks for throwing the question out to see where it would go. You are right about hearing the statements you posted in #1 - they were part of the standard vocabulary way back in the last century as I pursued “the path”. Interesting that those who have watched their own live the dream have similar outlooks - not always the case with CC discussions.
Here is a variant: my daughter went to her teacher a few years back (mid college) and said “I tried to quit this week.” She hasn’t been able to yet. It’s kind of a family joke at this point. I have no idea what is going to happen and don’t think about it much: she will have to once the funded years end!
In my opinion, if you are sending your child to study music at a “music school” do just that. Trying to have a more “practical” major goes out the window the day you agree to support their passion. If you are going to support them in their dream do it wholeheartedly! If you need your child to have a Plan B at this point, you may want to rethink your decisions.
I don’t think it is so black and white. I know dedicated musicians who went to college rather than conservatory and are not doing an MM or DMA or whatever. Some kids have multiple interests. They continue to study and practice and go to lessons for music but might major in something else entirely, or in addition to music, not because of a Plan B but out of interest. They may be no less passionate about music and may go on to do very well. I just don’t think it is either/or. Also, I hate to say it, but some conservatories are expensive and don’t have much aid, merit or financial, so reality hits after any acceptances roll in.
I was talking strictly about those going to a conservatory/music school.
Anthony Hopkins expressed this idea differently. He said if you really want to be an artist don’t have something to fall back on because if you do, you will. His thought was that it is so difficult to be an artist that if you have a way to opt out, you will probably take it.
My son agonized about studying music because he was worried that he would not be able to make a living. But he also said he would not be happy without music in his life. He decided to major in music business instead of doing a performance degree. Along his travels, he started working in music libraries at his school and another school.
Now his plan is to see if he can get a part-time job at a music library and be a working musician. I don’t see the library thing as a Plan B. It’s part of the plan A. Things evolve.
Excellent quote!