WATCH: Billie Eilish, a self-described environmental activist, performs at the DNC

Musician Billie Eilish, a self-described environmental activist, performed the song, "My future," after warning viewers that, "Donald Trump is destroying our country and everything we care about."

Watch the performance in the player above.

The convention featured several young climate activists, who praised Biden's $2 trillion plan to invest in clean energy and to end carbon emissions from U.S. power plants by 2035, even though his proposals don't go as far as their preferred "Green New Deal."

Wednesday's convention offered more focus on Biden's policy prescriptions than past nights, starting with gun violence and climate change, two issues that particularly resonate with younger voters.

It remains to be seen whether the unconventional convention will give Biden the momentum he's looking for.

Beyond the carefully scripted confines of the virtual convention, there were modest signs of tension between the moderate and progressive wings of Biden's Democratic Party.

In particular, some progressives complained that pro-Biden Republicans such as Ohio Gov. John Kasich have been featured more prominently than the party's younger progressive stars like New York Rep. Alexandria Ocasio-Cortez.

Climate activists also complained that the party appeared ready to drop a provision in the platform that calls for an end to fossil fuel industry subsidies and tax breaks.

The pandemic has forced Biden's team to abandon the traditional convention format in favor of an all-virtual affair that has eliminated much of the pomp and circumstance that typically defines political conventions. It's also produced opportunities to create new traditions, including a roll call vote for Biden's formal nomination featuring a video montage of activists in every state in the nation.

The Democratic convention will build to a finale Thursday night when Biden will deliver his acceptance speech in a mostly empty convention hall near his Delaware home.