Demi Lovato told fans they would have to help her hit the high notes as she returned to the stage after cancelling shows due to illness.
The US singer had to call off concerts in London and Birmingham in recent days as she was ill and suffering from swollen vocal cords.
She went ahead with her show at the SSE Hydro in Glasgow on Wednesday night, after posting a message on Twitter saying she was improving.
“I feel sooooo much better, thank you for all your well wishes!!!! You guys are the best!!!” she said.
“I still have to protect my voice so y’all may have to hit the high notes for me tonight.”
Lovato had been due to take to the stage at the O2 in London on Sunday and Arena Birmingham on Tuesday.
After cancelling the concert at the O2, the star said she was broken-hearted about disappointing her fans.
She said on Twitter: “I write this through tears of frustration and sadness that I have to postpone my concert in London at the O2 tonight due to being very, very sick and with swollen vocal chords that were examined by an ENT (dr.).
“If I go on tonight and injure my vocal chords any more I could potentially have to cancel the rest of my tour.
“I’m so so so sorry to disappoint any of my fans in London that have traveled hours to be here by plane or car, and to all of the fans that got these tickets for their birthday, holiday or any other special occasion.
“It breaks my heart to let you down. Just know I feel your frustration and I wouldn’t do his unless I absolutely had to.
“For everyone who bought a ticket to tonight’s show, I will see you for the rescheduled date on June 25th after Madrid and Rock in Rio.
“Thank you for understanding. I love you.”
The London show was rescheduled for June 25 and the Birmingham show will take place on June 29.