Have you tried using the musical provision you currently have but adding occasional ‘new styles of hymn’ along with the tried and tested traditional.
Have you heard of the music of The Iona Community? They have produced many hymns, choruses and songs with a gutsy kind of theology that can sometimes be ‘awakening’ or even ‘shocking’, (though not heretical), to a really stolid ‘traditional’ congregation.
Have you heard of Taize style choruses. A bit repetative but quite good during public prayers and meditation on the scriptures.
I would suggest you form a small group of interested musicians and church leaders who are willing to work hard at discovering through prayer and a lot of practice, ways in which your church can be introduced to new words and music without being made to feel that they have been ‘doing it wrong all these years and need to start worshipping God properly at last’.
You know what I mean, don’t you?