Testament guitarist Eric Peterson and Canadian celtic metal singer Leah have teamed up to bring the powerful track "Winter Sun" right in time for the start of winter. The song, premiering right here at Loudwire, blends the atmospheric and ethereal voice of Leah with Peterson's moody lead work, trading off melodies back and forth in true duet fashion.

"Winter Sun" gradually builds in intensity, shifting from delicate and welcoming to, ultimately, dark and pensive. The opening lines paint a gorgeous picture of the transitioning of seasons: "Crystal icicles /  glimmering in this cold dark heart / leaves are falling leaving naked / trees to warm a fire." Winter is welcomed, but by the song's end, we're treated to Peterson's familiar body of work with a brief heavy segment accented by foreboding choirs, almost to signal the potential doom that winter can spell.

“Leah and I orchestrated the vocals, drums, guitars and bass by leaving each other voice messages that you can record and can leave/make decent recordings of clips of music through WhatsApp,” Peterson says of the recording process. “Also, the sound quality is sharp enough that you can actually hear the dynamics well. It's truly amazing! It's a free app, so between Canada and Germany and Slovenia, that's some savings for sure! Pretty awesome!”

Leah adds, “I'm so excited about how technology has changed the music industry. Suddenly people are able to collaborate from all around the world and produce incredibly high-quality material. The possibilities are endless. Even something as simple as an app on a smart phone has completely revolutionized the way we write music." Describing her personal experience, she continued, "As a busy artist and mother of five kids, it was vital for me to be able to quickly record my vocal and lyric ideas and literally sing them into WhatsApp and fire it off to Eric in seconds. It made this song entirely possible.”

Though the duo are the stars of the song, they enlisted members of Peterson's black metal outfit Dragonlord — drummer Alex Bent, bassist Tilen Hudrap and keyboardist Lyle Livingston -- to round out the recording. Peterson and Leah also worked together in 2013, penning the track "Dreamland" which can be downloaded here.

More From Loudwire