Miranda Lambert says she’ll begin filming the video for her new single, ‘Over You,’ this week. The song — about husband Blake Shelton‘s late brother — is already a Top 30 hit on the Billboard charts.

“Video shoot for “Over You” tomorrow. Gonna be a hard one. But beautiful and heartfelt,” she tweeted late Sunday night. She and Shelton wrote the song together. His older brother Richie was killed in a car accident when the singer was 15-years-old.

“You know I cry every time I listen to it,” Lambert tells Taste of Country. She put the song on her ‘Four the Record’ album because her husband knew that there was no way he could perform it, should he include it on a future project. “I think that’s the most personal song that as a couple we’ve ever put out.”

For other reasons, the singer will be holding a heavy heart as she shoots the clip. In addition to losing her father-in-law earlier this month, she recently lost a friend she’d had since the third grade. “My friend is Mark Adams,” she tweeted. “We became friends at 9 years old. He was a great person. He is now in heaven with his dad.”

There is no word on when the video for ‘Over You’ will be released. Lambert resumes the On Fire Tour with Chris Young and Jerrod Niemann on Thursday in Huntsville, Ala.