'There is a disdain for composers...who borrow elements from one piece and bring them into the next ones'
Claude Baker - Composer (From 'The Muse that Sings' by Ann McCutchan)
Demands for originality of ideas and approaches, demands for a 'new model every year', can hinder or even stop in their tracks the long-term reflection, thinking and development that leads to truly valuable and ground-breaking innovations.
Such demands can also blind us to the most obvious 'just right' solution to a problem.
Composers develop their personal styles over many, many years, taking elements of their style and approach, and sometimes even specific musical themes that they find attractive, intriguing or otherwise significant in some way, and reworking them in subsequent pieces.
The Baroque composer Handel is probably the best known re-user of his own (and others') musical material. This habit enabled him to not only write an immense amount of music to order but also, through repeated rearranging and improving, 'take pebbles and polish them into diamonds'.
More recently, the mid 20th Century composer Erich Wolfgang Korngold reused music from previously written film scores to create fully fledged concert pieces. His Violin Concerto, which uses and develops music from four of his film scores, is probably the best known example of this.
If audiences, commissioners and critics ceaselessly demand 'something original' from composers, insisting upon shiny eye catching baubles to add to fashionable collections rather than carefully cut diamonds that, through the care of their crafting, offer superior and unique quality, the steady and sustainable evolution of composers' individual styles (and the priceless creativity that eventually blossoms from them), will be interrupted, curtailed, stopped.
Also (and just as importantly) a forced and blinkered focus upon being original can cut off a composer's line of sight towards that most simple but joyous of phrases, that most simple but striking of rhythms and harmonies, that briefest but most timely of pauses, that most straightforward but powerful of climaxes, that most obvious but attractive reworking of a piece.
If John Adams had put originality at the forefront of his thinking he would not have written Grand Pianola Music, so depriving audiences of its energy and vitality and the immediate and infectious joy of its final movement melodies. If Beethoven had fretted about being original he would not have used the most simple and ubiquitous of rhythms and harmonies to open his 5th Symphony, or paused most obviously but dramatically between their iterations. If Christopher Rouse had prioritised originality he would not have allowed Prokofiev's 'Montagues and Capulets' movement from the ballet Romeo and Juliet to so obviously (and powerfully and effectively) influence the climactic moments of no less then three of his orchestral works. If Max Richter feared unwarranted ridicule for being unoriginal he would not have reworked Vivaldi's Four Seasons, successfully reinventing it for a new generation of listeners.
So originality, as an aspect of musical composition, is over-rated, and when it becomes valued above all else it stupefies, stalls and stops the creative process.
This is true for not only musical composition but also all creative thinking and problem solving.
To think 'outside the box' you do not always have to be totally original. Like Handel, Korngold and the other composers mentioned above, look for existing ideas and approaches you can build upon, combine and use in new ways.
And put incessant demands for originality 'back in their box'.