There are two primary approaches to constructing a solo on the guitar:  1) Work it out in advance  2) Improvise.

Regardless of the method you’re using, it can help to think of the solo as a structure that has a beginning, a middle and an end and not just a flurry of scale notes strung together.  I like to use writing and language analogies because we all use these techniques everyday, even if we’re not always aware of it.

Below are some ideas to consider when crafting a solo.  Keep in mind these are merely suggestions and some basic guidelines to help you develop a solo strategy.  There are no rules.  Learn the guidelines and then use your creativity to move beyond them.

Use Your Root Note

Your root note (tonic) can be both your capital letter and your period, the beginning and the end.  Starting a solo with the root note will reinforce the key of your chord progression and set you up for a satisfying return to the root note at the end of the solo.

Use the Vocal Melody

In literary terms, this would be a recurring theme.  You’d be surprised how many good solos are just a simple variation of the vocal melody.  Give a listen to Nirvana’s “Smells Like Teen Spirit”.  The guitar solo is almost a note for note copy of the vocal melody.  This technique is not only a helpful way to come up with a solo, it’s actually good song construction!  The vocal melody is often the most important aspect of a song.  Reiterating and expanding on it can really tie the song together and also take it to a new place.

Use the Rhythm Pattern

You could think of this as cadence.  If the song has any catchy hooks or rhythm patterns, either in the vocal melody or in the chord progression, try applying this rhythm to the notes of your solo.  This is a clever way to take an existing song element and re-introduce it in a new way.  If you don’t have an idea of what notes to play, start with the root note only.  Play just the root note using the rhythm pattern you’ve chosen and see how it sounds.  It can be surprising how effective one note can come across when played with an interesting rhythm.

Repetition Is Your Friend

As humans, we crave repetition.  It’s universal within our different types of expression.  In fact, the musical term for repetition is, you guessed it, repetition.  So don’t worry too much if you find yourself repeating a pattern or a lick.  In fact, try to embrace it.  Our ears are always searching for patterns to help us relate the new with the familiar.  That’s why choruses repeat themselves!  It brings us back to something known and comforting–something we’ve heard before.  As long as you’re not playing the same repeating pattern in every solo on every song, you’ll be fine.

Avoid Too Many Commas

And finally, know when to shut it down.  We’ve all heard the solo that doesn’t end.  It’s the run on sentence of guitar playing.  An age old show biz saying is “always leave them wanting more.”  A general rule of thumb for solo length is to play only as long as it takes to get out one full thought from beginning to end.  Finish your sentence and then hand it off to the next paragraph.