Notes, scales and chords are the building blocks of any guitar-based song. Even if you're not interested in the technical proficiency of guitar players like Steve Vai or Eric Johnson, it's still a good idea to know basic scale forms, like major, minor and pentatonic. Playing scales allows you to see how notes are linked to form melodies. If you're an advanced player, try randomizing the notes of an A minor scale to create a melody. This is an easy way to use the fundamentals of guitar to explore new songwriting terrain.
Chords and chord progression are the foundation of a song. Many of the most iconic songs ever written, like "Blowin' in the Wind" by Bob Dylan or "Free Fallin" by Tom Petty, are composed almost entirely of three chords.
For beginners, it's important to master the basic shapes, like the A, D, G, E and C chords. These shapes can be moved up and down the fretboard to produce a wide variety of unique-sounding chords. Learning these chord shapes and their variations is a great way to kick-start a songwriting session; they can be arranged in countless ways.
The same is true for advanced guitar players, with one exception. If you've already mastered the basic chord shapes and their variations, try altering them by lifting one of your fingers or by swapping finger positions. These slight alterations to established chord shapes can often produce surprising results, leading a song or a chord progression in a new direction.
One of the best songwriting strategies for an intermediate or beginning guitar player is emulation. Listen to Eric Clapton's "Wonderful Tonight" a few times, then learn the chord changes. Play along with the music and try to match Clapton's playing style as closely as possible. You'll gain insight into what makes the "feel" of the music so enjoyable, and more importantly, how Clapton's songwriting creates and enhances that feel. Write down the chord progressions; when you're learning someone else's songs, you'll often stumble upon chord shapes you'd like to use in your own work.
As an advanced guitar player, revisiting your heroes will often inspire and invigorate your writing. People naturally gravitate toward the simplest, quickest solution; the same is true for songwriters. Experienced guitarists often fall victim to writer's block, recycling chord progressions or melodies they're accustomed to playing. Play along to Ozzy Osbourne's "Crazy Train." Notice how inventive and inspired Randy Rhodes' guitar work is throughout the song--he dots each section with left-field flourishes like whammy dive-bombs or finger-tapping runs. Bring that spirit of creative fearlessness to your next writing session, and you're bound to see results.
At its essence, songwriting is musical storytelling. A list of great songwriters includes musicians from all eras and genres, like Mozart, Stravinsky, Sonic Youth, Aretha Franklin, Metallica and countless others. The secret to a great song often lies in its structure. Studying the structure of songs by legendary artists is an excellent way to understand the element of storytelling inherent in songwriting.
Repetition is the main ingredient of a song's structure. Verse, chorus, verse, chorus, bridge, chorus is a typical form found in popular music. Each section of this traditional format is designed to push the listener forward, much like chapters in a book. The chorus addresses the central melody or theme of the song, while the verse advances the plot of the song, typically through lyrical content.
Mastering song structure is challenging. As a beginner, the process should be similar to that outlined earlier. Listen to how your favorite artist structures a particular song, then emulate that exact form with your own chord progressions. Advanced players should experiment with traditional forms, keeping in mind the importance of repetition. Placing a verse where a chorus would go is often an effective way to subvert a listener's expectations.