Mel C is taking the lead when it comes to the Spice Girls' musical direction for their upcoming tour.

The 45-year-old singer - who is known as Sporty Spice in the group - has made it her ''priority'' to ensure that she and her bandmates Geri Horner, Mel B and Emma Bunton's vocals are in top shape for the shows by using the same musical director she worked alongside on her solo music.

A source told the Daily Mirror newspaper: ''The tour is going to have amazing costumes and epic staging, but Mel is passionate about the music and is adamant that the vocals are as much of a priority.

''The girls each have a House of Spice theme complete with groups of dancers branded as Baby, Scary, Ginger and Sporty, which will certainly entertain.

''But Mel insisted she brought in a musical director she has worked closely with on her solo material to boost the vocal performances and make sure the music hits the right note.''

The extensive stadium run - which won't feature Victoria Beckham - kicks off in Dublin on May 24 and it was recently reported that Geri, aka Ginger Spice, has hired her own singing coach.

The band, who have been working hard in rehearsals, haven't performed on stage properly together since the 2012 London Olympic Games Closing Ceremony, and the 'Bag It Up' hitmaker is determined to make sure their fans' get their money's worth.

An insider said: ''Geri is anxious to make sure she is up to standard when the girls get back together ... so she has hired a singing instructor.

''She doesn't want to be the one people point the finger at if it isn't note perfect.''

Geri's recruitment of a vocal instructor came after reports that Sporty ordered her bandmates to take singing lessons.

The Northerner was worried as the group have not sang together in years and she believes it is ''crucial they take the performance side of the money-spinning return very seriously''.

Geri also insisted that they never came close to asking fashion designer Victoria, 45, to join them on the road, even though Mel B claimed she was poised to sign up.

She said: ''No, there was never a point it was all five of us. Mel thought she could make it happen if she just kept on saying it. She's clever, you've got to hand it to her.''