I never learn how to read partitures. I'm starting being a songwriter so I think that I have to know how to read partitures. I play the guitar. By partitures I mean music written out for my instrument.
There will be little need to do this in the initial stages at least - and probably a lot further. Many 'songwriters' cannot even read or write music on one stave, but it hasn't stopped them writing very good songs.
Being able to write (and read) dots on a stave is going to be very useful, especially for communicating your songs to other musicians, who will appreciate that you know what you're talking about. But a demo is often what gets proffered instead. You play guitar, so a recording of that plus vox will do, minimally.
Should you wish to orchestrate your songs, then understanding scores, transcribing instruments and arrangements, then yes, embark on what will be a long, complex journey that will be very fulfilling, and may well save you lots of money by not needing to employ someone to do all that for you - and, since each song is your baby, you then get to help it grow up.
Bottom line - being able to read scores won't make you a better song writer, but will help you to write them out better, but will take a lot of time and effort. That's a choice you have to make!
Great question. Many others have wondered the same thing.
I am a songwriter and guitar player. I also compose the music to accompany the lyrics I write. So you could say I am a composer. I can't read music. I can figure out what note is on a music staff if I count the lines and spaces while saying "A B C D etc" and looking at the key signature.
Obviously you don't need to read music to compose lyrics. But to create a melody for the song, you don't need to be able to read music either. You just need to know what chords you are playing and how to write down the name of the chord. What I do is find (using my guitar and trial and error) a chord progression that seems to fit the mood of the song, write it out on a piece of paper, and then sing the melody over the chords, literally making it up as I go along.
Once I am happy with the way the melody that goes with the current chord sounds (up to the next chord change), I record myself singing that part of the melody while playing the chord. I repeat this process until I have created the melody for both the verse and chorus. I usually have a slightly different melody (and chord progression) for the verses than for the chorus and sometimes I might throw in a bridge (optional).
Once I have the melody for the entire verse and the entire chorus recorded, I can put them together and listen until I know how it goes. It's even easier than learning to sing a song you have in your music library. Then I record the entire song from beginning to end.
Now I have a demo. I can take that to a recording studio and someone who has spent way more time learning how to compose music and record and produce music than I ever want to spend - will take my rough demo and write out enough information to add all of the other accompanying instrument parts the song needs.
When I have my songs recorded in a studio, the producer will email me a "draft" of what his arrangement sounds like for me to approve. I can ask for changes if I want to (such as "slower tempo", "take out the piano", "put in a drum fill between the 2nd chorus and the bridge", etc.) Once I am happy with the tempo and instrument mix and dynamics, and timing of the chord changes - I will start practicing singing the vocals over the new fully produced "mix tape" (a karaoke version of my new song). Then I make an appointment to show up in the studio to record the vocals over the music. Eventually I end up with a fully produced, engineered and mastered song. If I wasn't a singer, I would hire a vocalist to cut the vocals.
There is so much more to learn about songwriting (that I believe is far more important) than learning how to read notes on a staff or partitures.
For example, as a songwriter you should know how to use tension and release to take the listener through the emotions you want your song to convey. You need to learn about how to make the chorus contrast with the verses. You need to know when a bridge might help your song and how to make it different than the chorus and verse melody. You should understand the anatomy of a song (the parts that go together to make a song). You need to learn about rhythm and how it impacts the feel and emotions of the song. You need to learn how to keep your songs singable. You need to learn how dynamics, and tempo work to convey different feelings. I could go on and on.
However, if you have the time and interest to learn to read music, it won't hurt to do so. As long as you don't get so bogged down and frustrated with the academic process of learning to read music, that you lose any passion you may have for becoming a guitar playing songwriter.
For more in depth and detailed information about the process I use to compose music and write songs, check out this (https://music.stackexchange.com/a/30175/16897)
For a much shorter simplified version of my song composing process click here (https://music.stackexchange.com/a/39284/16897)
To see my thoughts about how a strict academic approach to music education can diminish the joy of learning music and make it more like a chore than a passion, click here (https://music.stackexchange.com/a/39284/16897)
Whichever path you choose to becoming a songwriter, be sure you enjoy the journey! And good luck.
If you want to expand your musical horizons beyond 'strum and sing' I suggest you learn to play keyboard as well. Maybe not to a high level of performance, but well enough to play a melody AND a bass line - something that a guitar isn't really designed to do. And a very good way to experience a wide range of existing music is to read the notation of published copies.
Not that a lot of great songs weren't created by 'strum and sing' performers!
Not at all. If anything it's rare for guitarists to know how to read sheet music. Unless you're an academically trained classical guitarist and you're looking to play classical guitar exclusively.
Guitarists generally refer to TABs when they need a hint on how to play something.
In guitar, harmony is at the forefront. So people generally start off with learning chords. Learning chord progressions, and using your voice as the melody. That's why guitar is especially popular with singers and songwriters.
A few guitarists that couldn't read music: Eric Clapton, Slash, John Lennon, Paul Mccartney, Elvis, Jimi Hendrix, Eddie Van Halen, and many more.
If you want to be able to communicate your ideas to musicians who are not in the same room as you are, you'll need to be able to write them down. The exception would be other guitarists, who can listen to a recording of what you're playing and copy it.
If you want to be able to dictate accompaniments and arrangements so that others can accurately reproduce your ideas you'll either have to write them down or hire someone who is very patient and dedicated to your music to communicate for you. If you can't tell your colleagues and arranger exactly what you want then it becomes a collaboration and their artistry and ideas will be involved. That might not be a bad thing, either.
Do you NEED to? No. Is it very strongly recommended? Yes. Take Django Reinhardt, for example, as one of the most revered and most genius jazz guitarists of all time. Django, could not read anything related to music notation or music theory. Not TAB, not standard notation, nothing. What he did have, was an amazing "ear". By that I mean he could hear pitches, chords, chord progressions astonishingly well. Django Reinhardt was really an amazing musician with a formidable ear; truly one-of-a-kind, but because he was such a one-of-a-kind, his talents and expertise are exceedingly rare, so don't get your hopes up.