This is a very naive question, but I tend to perceive a song with a key signature that has more flats or sharps to be more difficult than the same song written in a key with fewer flats or sharps.
Is this the typical case and if so why do the sharps and flats make the song more initially intimidating?
Every instrument has keys that are easy to play and and keys that are not very easy to play in. There are even transposing instruments that are built to play in a certaint key natrually that isn't in the key of C so for some instruments playing in the key of C, which has no sharps or flats, is actually harder. For example the first instrument I learned was the trumpet which is a Bb instrument so for me the first songs I learned were in Bb which were very easy to play on the trumpet.
There's another side of this question that I can understand especially when I was first learning to read music which is as you deal with more accidentales pieces get harder to read and that is understandable especially when you have a lot of accidentals outside they key you are in. As you get more comfortable reading music, a piece that you thought was in a harder key to play might have just been harder for you to sight read initially and is actually easier to play then something in then a key with less accidentals.
Yes, I think it's generally true for a simple reason: we all (well just about all) learn to read the notes of the staff initially in their default, natural position. We learned our "Every Good Boy Does Fine" and so forth before we learned our sharps and flats. When we do learn about sharps and flats, they're presented as exceptions to what happens normally. Which is baked right into our notational system: "This line is B. Except when it's got this doohicky on it, then it's a B flat."
So when we read a score in some key that has sharps and flats (i.e. not C maj, A min, etc.) we treat the sharps and flats as exceptions to the rule we learned. "Ah, we're in G major, so I have to keep track of the fact that every time I see something that looks like a note on F, it should actually be played as an F#." And here's the thing: remembering exceptions to a rule increases the cognitive load of a task by a whole bunch.
It may not be any harder to play once you have it down, and, say, have it memorized. But getting it off the page and into your instrument in the first place will always take at least a little bit more cognitive effort than it would to read something with fewer sharps and flats, even if one is very fluent at reading. If one is not very fluent at reading, every additional black note is going to increase the cognitive load by quite a bit.
I can definitely understand why some keys appear to be more intimidating than others, but this intimidation is most likely caused by a lack of familiarity. For example, consider the sentence "I adumbrated a plan so vague that my fellow politicians slapped my back in approbation." This sentence seems fairly intimidating, especially if you aren't familiar with the words adumbrated and approbation, but as you get more familiar with these words they seem less intimating and hopefully become a part of your vocabulary. In other words as you get more familiar with different keys they will become part of your vocabulary so to speak and unsurprisingly like these words it takes some time to get familiar with them.
What key signatures are "easier" can depend on what instrument you're playing and on whether you mean "easy to read" or "easy to sound the notes". It may also depend on what you're used to.
On the piano, I like pieces with a few sharps or flats in the key signature because it is easier to pass the thumb under when you are going from a black key to a white key than going from white to white. The C major scale may be the easiest to learn, but I find it the hardest of all the major scales to play well.
It's also easier to strike a black key than a white key at the upper or lower end of a chord without also striking an adjacent key, or to strike two adjacent black keys reliably with one outstretched finger while not accidentally striking a third key.
Once I am familiar with a certain key signature, I don't find it significantly harder to read than C major, because I have learned through practice to associate a note written on a particular line of the staff with a particular key on the keyboard, which may be one of the black keys. What is more difficult sometimes is to change from one key to another in the middle of a piece, even if the change is to a key with fewer sharps or flats. But if you have only ever played pieces written in C major on a piano, and you are suddenly presented with something written in A-flat major (four flats), of course it will be intimidating.
Individual sheet music for some band instruments is often written in a different key than the key in which the music is actually played. For example, if the piece the band is playing is actually in E-flat major, some instruments will be playing from sheet music with no flats at all, that is, the music is written in C major but the instrument itself transposes the notes to E-flat major. That is, the musicians are taught to finger the instrument in a certain way when they read the note C on the sheet music, and the actual sound produced is an E-flat. (Another instrument from the same series, fingered the same way, will produce a B-flat.)
If the band actually plays a tune in C major, the E-flat instruments will be reading music with three sharps in the key signature, and their fingerings may be more difficult. So those instruments may be significantly easier to play in keys with three or four flats (considering the key in which the actual sounds of the music are produced) than in keys with no more than one sharp or flat.
I believe this is very subjective and varies from musician to musician. To give you an example, I play the trombone (Bb key) and while learning the instrument flats where more common than sharps, so that's what I grew more used to it. In fact, I wouldn't even say it's hard to play the sharps. What is hard is reading when there are a lot of sharps in there, so it's really more about what's more common in your perspective. After all, for every flat, there's a corresponding sharp and vice versa.
You can achieve a certain paradigm shift when you realise that scales are just a series of notes a set amount of semitones / intervals from the root note.
The Major scale for instance has it semitones between the 3/4 and 7/8 scale degrees. So if you have 8 notes starting and ending on the same letter name with semitones at these places then you have a Major scale.
That being said there should be no need for this to be difficult if your theoretical foundations are well met. Reading the OP makes me feel that this is the root of your problem.
I hope these assumptions for what makes a piece with several accidentals in its key signature harder to read (and therefore harder to play) apply to pretty much everyone who reads music with key signatures:
Now to find various reasons why either of the above can occur in music, and therefore, whether music with several sharps in the key signature or several flats is harder to read:
We'll need to analyze how often the four are used in music--and how often people just use enharmonic equivalents instead (such as A-C#-E for the Neapolitan of A flat major)--to fully determine whether music in key signatures with several sharps or with several flats is harder to read overall.
This depends on what you are used to. When playing in orchestra, it is often so that the most common keys are with 2, 3 or 4 flats (Bb, Eb and Ab). This cause many flute players to be more comfortable with having some flats, than playing in C that is without any flats or sharps.
That said, I play in a wind orchestra where we often play with pop artists, and our conductor arrange the music for the orchestra. For pop/rock music, it is more common with sharps in the signature, because this is more easy for guitar players, where common keys are G, D, A and E.
So we have actually become quite familiar with playing pieces with a lot of sharps, which become A LOT of sharps for Bb instruments (clarinets, trumpets etc.) and Eb instruments (saxophones)...
I feel the same as Codeswitcher:
For me, remembering which of the black notes to play when dealing with more than 3 or 4 sharps or flats has always been tough. I would appreciate any suggestions in learning how to read the music while my brain is also interpreting each note that should be a sharp or flat. (Other than manually adding the sharps and flats next to every note in the piece). I feel the same way when trying to think ahead more than 3 or 4 moves in chess.
