Derulo is battling accusations he owes credit to guitarist-producer Matthew Spatola for work on the chart-topping song Jason Derulo took the witness stand in a federal courtroom in downtown Los Angeles Thursday and denied claims he stiffed guitarist-producer Matthew Spatola out of writing credit and royalties on his chart-topping hit “Savage Love.” “Mr. Spatola created nothing on ‘Savage Love,’” Derulo said, asserting that he hired Spatola only as a session musician for two three-hour sessions in April 2020. At the time, Derulo said, he was developing the track based on the viral “Laxed – Siren Beat” melody by New Zealand artist Jawsh 685, which had surged across social media and fueled an international dance craze early in the pandemic. Though Spatola testified earlier in the trial that Derulo called him prior to the recording session and specifically invited him to come “create” a new version of the song together, Derulo testified that never happened.…