A few years back, there was a surge of metal bands with female lead singers. A lot of these bands possessed other similar characteristics, most notably elements of their sound. Because of the almost pop nature of the music and the female lead singers, this scene became derogatively referred to as "prom dress" metal.
A lot of the bands played similar, if not identical, styles of metal. It was mostly gothic metal with a mixture of other elements thrown in for good measure: power metal, symphonic metal, and others. Below, I will discuss a few of these bands.
At this point, the Italian band Lacuna Coil is the leader of the pack. The reason is simple: Cristina Scabbia. Metalheads the world over have fallen in love with Cristina who is as beautiful as she is talented. The band played a type of gothic metal that was dark and melodic and Scabbia's voice sultry and powerful. Unfortunately, they have begun falling out of favor with a lot of their earlier fans as they have been getting more mainstream attention. The reason for this is simple as well: the music is not as inspired as it was in the early years. Lacuna Coil has gone the Evanescence route towards mainstream pop-rock ditching much of their metal influences in the last few years. A shame, their early material was very impressive.
Another very well-known band, Finnish power metal band Nightwish has suffered a bit in recent years due to the change in singers. Tarja Tarunen was the band's initial singer and her voice was an extremely gorgeous operatic soprano. The musicians were among the most talented in the scene and took the songwriting craft extremely seriously. The music was essentially a heavy metal symphony backing a very talented singer. Unfortunately, Tarunen was booted from the band and Annette Olzen took over in a much poppier direction. Seeing a pattern?
This Dutch gothic metal band has not done much to separate themselves from the rest of the scene. They do enough things reasonably well to garner some attention, but not well enough to be considered a better or more talented band than the two bands above. And they are falling victim to the same curse as the above bands by focusing their songwriting attention on being popular. Never the best strategy for metal bands. Sharen Den Adel is a fantastic singer, not as bombastic as Tarunen, nor as seductive as Scabbia, but she has her own style.
Easily the darkest sound of the scene, the Norwegian group Tristania features a multitue of singers. Vibeke Stene is just the focal point. The band also features a couple of male singers to perform various types of vocals, as well as a choir to fill in. The sound is creepy and surprisingly brutal. The band plays dark symphonic-influenced gothic metal with an interplay of vocalists and musical parts. Less a band, and more of a traveling metallic opera. Tristania unfortunately is also suffering an identity crisis as Stene and one of the main songwriters have left the band in recent years. A shame, because their last album with Stene was quite possibly their strongest.
The German-Norwegian viking/gothic metal band is one of the newer bands in the genre. The band plays a style of music that is a little more aggressive than the above bands, featuring a strong songwriting team, and heavy guitars. Liv Kristine has a strong voice, which is a little more of a submissive sound than overpowering the music. It's somewhat appropriate for the lyrical them, which deals with the Viking woman, at least on their Vinland Saga album. Kristine's husband Alexander Krull is the guitarist and growler in the band, while her sister is in the band Midnattsol. Quite the musical family.Other bands who have been erroneously placed in the genre are The Sins of Thy Beloved and Draconian who are both much closer to doom metal than gothic metal and whose female singers are more backup singers. I did not discuss Epica as I do not own an album by them, nor have I heard enough to be able to discuss them.
In recent years, there have been many more bands featuring female lead singers in a variety of genres. Death metal (Arch Enemy, Estuary, Dreaming Dead), black metal (Gallhammer, Sigh, sort of), thrash metal (Pyrotoxic), metalcore (The Agonist, Straight Line Stitch), and traditional metal (Benedictum, Temtris, Ignitor). Women are starting to catch up in heavy metal.