Lauren Pazienza — the woman accused of shoving an 87-year-old voice coach to her death — was tossed behind bars by a Manhattan judge on Tuesday.

Pazienza, who was out on $500,000 bail her mom posted, remained stone-faced as the judge ordered her to be held in jail pending trial during a hearing in Manhattan Supreme Court.

The 26-year-old Long Island native pleaded not guilty through her lawyers on an indictment charging her with first-degree manslaughter and two counts of second-degree assault in the death of Barbara Gustern.

Pazienza, an event organizer and scion of a lucrative cesspool empire, allegedly called Gustern a “bitch” before allegedly pushing the elderly woman in Chelsea in an unprovoked attack on March 10, police said.

The octogenarian fell and hit her head, dying from her injuries five days later.

Manhattan Supreme Court Justice Felicia Menin remanded Pazienza during her arraignment on the indictment. She faces between five and 25 years behind bars if convicted.

Gustern was a vocal coach whose clients included Blondie’s Debbie Harry.