Many demos feature tracks with long running times that aren’t always justified by the quality of the writing in their chosen musical genres. The progressive rock bands of yesteryear were often derided for their long, seemingly self-indulgent compositions and (sometimes) tedious soloing. Today’s long mixes are aimed at a different audience with a different mindset, but they can be just as boring when repetition replaces inspiration in the arrangements. That repetition can also include the cliched use of dynamics, effects, and editing tricks. As the composer Rossini once said, “Wagner had some wonderful moments, but awful half hours.”
Keep in mind that even when lying on the beach, record executives are always “too busy” when it comes to listening to unsolicited demos. If you don’t impress them in the first 10-30 seconds, you certainly won’t capture their imagination with a four-bar phrase repeated for five minutes.