On Paraiso Express, his eighth studio album to date, Alejandro Sanz returns to the soft rock style for which he's best known, the sound of his most successful albums, the million-sellers Más (1997) and El Alma al Aire (2000).

While those albums and their three predecessors, Viviendo Deprisa (1991), Si Tú Me Miras (1993), and 3 (1995), made Sanz the most commercially successful Spanish singer of all time, he veered off in new directions after the turn of the century with No Es Lo Mismo (2003) and El Tren de los Momentos (2006).

These two albums, both produced by Lulo Pérez, are highly collaborative, often daring, and downright experimental relative to Sanz's prior work.

These albums spawned their share of major hits, "No Es Lo Mismo" and "A la Primera Persona" in particular, yet they also alienated some of his fan base.

To the sure delight of those alienated fans who prefer his soft rock style, no longer is Sanz pushing stylistic boundaries like he did on No Es Lo Mismo and El Tren de los Momentos under the guidance of Pérez.

On Paraíso Express, he chose to collaborate instead with producer Tommy Torres, best known for his acclaimed work with Ricardo Arjona.

Paraíso Express consequently often sounds reminiscent of Arjona's recent work, the excellent album 5to Piso (2008) in particular.

This is a good fit for Sanz, who like Arjona is a talented singer/songwriter in need of a capable musical arranger with whom he can collaborate.

The similarities between 5to Piso and Paraíso Express are most evident on the soaring ballad "Desde Cuándo," which sounds like a take on Arjona's smash hit "Como Duele." Yet for all the similarities between Paraíso Express and 5to Piso, there is the lead single "Looking for Paradise," a bilingual collaboration between Sanz and American R&B singer Alicia Keys.

Demonstrating the same willingness to break free of boundaries that Sanz showcased on his past couple albums, "Looking for Paradise" is a fantastic collaboration that is well-sequenced three tracks into Paraíso Express and goes a long way toward diversifying the album's style and tone.

At ten tracks in length and 42 minutes in duration, Paraíso Express is a fairly brief album, so "Looking for Paradise" stands tall amid the other songs, all of which are sung solo.

There are plenty of highlights besides "Desde Cuándo" and "Looking for Paradise"; in fact, this is an album with very few weak links, just a couple songs sequenced late where the tempo drags a bit.

With the exception of the collaboration with Keys on "Looking for Paradise," Paraíso Express doesn't offer many surprises overall for fans of Sanz, some of whom may have been put off by the experimentation of his past couple albums, especially El Tren de los Momentos.

Indeed, the biggest surprise of this album is how it finds Sanz returning to the soft rock style that brought him so much success a decade ago -- not exactly, however, as the Arjona-esque production work of Torres differentiates Paraíso Express from albums like Más and El Alma al Aire, whose stuffy arrangements now sound passé in light of Sanz's edgy work with Pérez in recent years, not to mention his affiliation with Shakira.